Transmission method, transmission device, reception method, and reception device

ABSTRACT

Embodiments include devices and methods that improves quality in radio transmission/reception using a single-carrier scheme and/or a multi-carrier scheme.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/182,798, filed Feb. 23, 2021, which is a continuation of U.S. patentapplication Ser. No. 16/848,057, filed Apr. 14, 2020, which is acontinuation of U.S. patent application Ser. No. 16/448,607, filed Jun.21, 2019, which is a continuation of U.S. patent application Ser. No.16/079,693, filed Aug. 24, 2018, which is a 371 U.S. National Phase ofPCT International Patent Application No. PCT/JP2017/007372, filed Feb.27, 2017, which claims priority to U.S. Patent Application No.62/301,055, filed Feb. 29, 2016. This application also claims thebenefit of Japan Patent Application No. 2017-025126, filed Feb. 14,2017. The disclosures of which are herein incorporated by reference intheir entireties for all purposes.

TECHNICAL FIELD

The present disclosure relates to a transmission method, a transmissiondevice, a reception method, and a reception device.

BACKGROUND OF THE INVENTION

As radio communications schemes, single-carrier schemes andmulti-carrier schemes such as OFDM (orthogonal frequency divisionmultiplexing) (for example, see Patent Literature (PTL) 1) have beenproposed. Multi-carrier schemes are advantageous in that they provide ahigh frequency-usage efficiency and are suitable for large-capacitytransmission. Single-carrier schemes are advantageous in that they donot require signal processing such as FFT (fast Fourier transform) orIFFT (inverse FFT), and are thus suitable for realizing a low powerconsumption implementation.

CITATION LIST Non-Patent Literature

NPTL 1: J. A. C. Bingham, “Multicarrier Modulation for DataTransmission: An Idea Whose Time Has Come,” IEEE CommunicationsMagazine, May 1990.

BRIEF SUMMARY OF THE INVENTION Technical Problem

In radio communication using a single-carrier scheme and/ormulti-carrier scheme, a technique for improving data reception qualityis desired.

Solutions to Problem

A transmission method according to one aspect of the present disclosuresincludes a mapping step, a signal processing step, and a transmissionstep. In the mapping step, a plurality of first modulated signals s1(i)and a plurality of second modulated signals s2(i) are generated fromtransmission data, where i is a symbol number that is an integer greaterthan or equal to 0, the plurality of first modulated signals s1(i) aresignals generated using a QPSK modulation scheme, and the plurality ofsecond modulated signals s2(i) are signals generated using 16QAMmodulation. In the signal processing step, a plurality of firstsignal-processed signals z1(i) and a plurality of secondsignal-processed signals z2(i) that satisfy a predetermined equation aregenerated from the plurality of first modulated signals s1(i) and theplurality of second modulated signals s2(i). In the transmission step,the plurality of first signal-processed signals z1(i) and the pluralityof second signal-processed signals z2(i) are transmitted using aplurality of antennas. Among the plurality of first signal-processedsignals z1(i) and the plurality of second signal-processed signalsz2(i), a first signal-processed signal and a second signal-processedsignal that have identical symbol numbers are simultaneously transmittedat the same frequency.

A transmission device according to one aspect of the present disclosuresincludes a mapper, a signal processor, and a transmitter. The mappergenerates a plurality of first modulated signals s1(i) and a pluralityof second modulated signals s2(i) from transmission data, where i is asymbol number that is an integer greater than or equal to 0, theplurality of first modulated signals s1(i) are signals generated using aQPSK modulation scheme, and the plurality of second modulated signalss2(i) are signals generated using 16QAM modulation. The signal processorgenerates a plurality of first signal-processed signals z1(i) and aplurality of second signal-processed signals z2(i) that satisfy apredetermined equation from the plurality of first modulated signalss1(i) and the plurality of second modulated signals s2(i). Thetransmitter transmits the plurality of first signal-processed signalsz1(i) and the plurality of second signal-processed signals z2(i) using aplurality of antennas. Among the plurality of first signal-processedsignals z1(i) and the plurality of second signal-processed signalsz2(i), a first signal-processed signal and a second signal-processedsignal that have identical symbol numbers are simultaneously transmittedat the same frequency.

A reception method according to one aspect of the present disclosureincludes a reception step and a demodulation step. In the receptionstep, reception signals are obtained by receiving a first transmissionsignal and a second transmission signal transmitted from differentantennas. The first transmission signal and the second transmissionsignal are signals resulting from transmitting a plurality of firstsignal-processed signals z1(i) and a plurality of secondsignal-processed signals z2(i) using a plurality of antennas, where i isa symbol number that is an integer greater than or equal to 0, and amongthe plurality of first signal-processed signals z1(i) and the pluralityof second signal-processed signals z2(i), a first signal-processedsignal and a second signal-processed signal that have identical symbolnumbers are simultaneously transmitted at the same frequency. Theplurality of first signal-processed signals z1(i) and the plurality ofsecond signal-processed signals z2(i) are signals generated byperforming first signal processing on a plurality of first modulatedsignals s1(i) generated using a QPSK modulation scheme and a pluralityof second modulated signals s2(i) generated using 16QAM modulation. Theplurality of first signal-processed signals z1(i) and the plurality ofsecond signal-processed signals z2(i) satisfy a predetermined equationin regard to the plurality of first modulated signals s1(i) and theplurality of second modulated signals s2(i). In the demodulation step,the reception signals are demodulated by performing second signalprocessing corresponding to the first signal processing.

A reception device according to one aspect of the present disclosureincludes a receiver and a demodulator. The receiver obtains receptionsignals by receiving a first transmission signal and a secondtransmission signal transmitted from different antennas. The firsttransmission signal and the second transmission signal are signalsresulting from transmitting a plurality of first signal-processedsignals z1(i) and a plurality of second signal-processed signals z2(i)using a plurality of antennas, where i is a symbol number that is aninteger greater than or equal to 0, and among the plurality of firstsignal-processed signals z1(i) and the plurality of secondsignal-processed signals z2(i), a first signal-processed signal and asecond signal-processed signal that have identical symbol numbers aresimultaneously transmitted at the same frequency. The plurality of firstsignal-processed signals z1(i) and the plurality of secondsignal-processed signals z2(i) are signals generated by performing firstsignal processing on a plurality of first modulated signals s1(i)generated using a QPSK modulation scheme and a plurality of secondmodulated signals s2(i) generated using 16QAM modulation. The pluralityof first signal-processed signals z1(i) and the plurality of secondsignal-processed signals z2(i) satisfy a predetermined equation inregard to the plurality of first modulated signals s1(i) and theplurality of second modulated signals s2(i). The demodulator demodulatesthe reception signals by performing second signal processingcorresponding to the first signal processing.

Advantageous Effect of Invention

According to the present disclosure, it is possible to improve datareception quality is desired in radio communication using asingle-carrier scheme and/or multi-carrier scheme.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates one example of a configuration of a transmissiondevice.

FIG. 2 illustrates one example of a configuration of a signal processorin a transmission device.

FIG. 3 illustrates one example of a configuration of a signal processorin a transmission device.

FIG. 4 illustrates the capacity for each SNR in an AWGN environment.

FIG. 5 illustrates one example of a configuration of a radio unit in atransmission device.

FIG. 6 illustrates one example of a frame configuration of atransmission signal.

FIG. 7 illustrates one example of a frame configuration of atransmission signal.

FIG. 8 illustrates one example of a configuration of components relevantto control information generation.

FIG. 9 illustrates one example of a configuration of an antenna unit ina transmission device.

FIG. 10 illustrates one example of a frame configuration of atransmission signal.

FIG. 11 illustrates one example of a frame configuration of atransmission signal.

FIG. 12 illustrates one example of a symbol arrangement method withrespect to the time axis.

FIG. 13 illustrates one example of a symbol arrangement method withrespect to the frequency axis.

FIG. 14 illustrates one example of a symbol arrangement method withrespect to the time and frequency axes.

FIG. 15 illustrates one example of a symbol arrangement method withrespect to the time axis.

FIG. 16 illustrates one example of a symbol arrangement method withrespect to the frequency axis.

FIG. 17 illustrates one example of a symbol arrangement method withrespect to the time and frequency axes.

FIG. 18 illustrates one example of a configuration of a radio unit in atransmission device.

FIG. 19 illustrates one example of a configuration of a receptiondevice.

FIG. 20 illustrates one example of the relationship between atransmission device and a reception device.

FIG. 21 illustrates one example of a configuration of an antenna unit ina reception device.

FIG. 22 illustrates one example of a configuration of a transmissiondevice.

FIG. 23 illustrates one example of a configuration of a signal processorin a transmission device.

DETAILED DESCRIPTION OF THE INVENTION Embodiment 1

A transmission method, transmission device, reception method, andreception device according to this embodiment will be described indetail.

FIG. 1 illustrates one example of a configuration of a transmissiondevice according to this embodiment, such as a base station, accesspoint, or broadcast station. Error correction encoder 102 receivesinputs of data 101 and control signal 100, and based on informationrelated to the error correction code included in control signal 100(e.g., error correction code information, code length (block length),encode rate), performs error correction encoding, and outputs encodeddata 103. Note that error correction encoder 102 may include aninterleaver. In such a case, error correction encoder 102 may rearrangethe encoded data before outputting encoded data 103.

Mapper 104 receives inputs of encoded data 103 and control signal 100,and based on information on the modulated signal included in controlsignal 100, performs mapping in accordance with the modulation scheme,and outputs mapped signal (baseband signal) 105_1 and mapped signal(baseband signal) 105_2. Note that mapper 104 generates mapped signal105_1 using a first sequence and generates mapped signal 105_2 using asecond sequence. Here, the first sequence and second sequence aredifferent.

Signal processor 106 receives inputs of mapped signals 105_1 and 105_2,signal group 110, and control signal 100, performs signal processingbased on control signal 100, and outputs signal-processed signals 106_Aand 106_B. Here, signal-processed signal 106_A is expressed as u1(i),and signal-processed signal 106_B is expressed as u2(i) (i is a symbolnumber; for example, i is an integer that is greater than or equal to0). Note that details regarding the signal processing will be describedwith reference to FIG. 2 later.

Radio unit 107_A receives inputs of signal-processed signal 106_A andcontrol signal 100, and based on control signal 100, processessignal-processed signal 106_A and outputs transmission signal 108_A.Transmission signal 108_A is then output as radio waves from antennaunit #A (109_A).

Similarly, radio unit 107_B receives inputs of signal-processed signal106_B and control signal 100, and based on control signal 100, processessignal-processed signal 106_B and outputs transmission signal 108_B.Transmission signal 108_B is then output as radio waves from antennaunit #B (109_B).

Antenna unit #A (109_A) receives an input of control signal 100. Here,based on control signal 100, antenna unit #A (108_A) processestransmission signal 108_A and outputs the result as radio waves.However, antenna unit #A (109_A) may not receive an input of controlsignal 100.

Similarly, antenna unit #B (109_B) receives an input of control signal100. Here, based on control signal 100, antenna unit #B (108_B)processes transmission signal 108_B and outputs the result as radiowaves. However, antenna unit #B (109_B) may not receive an input ofcontrol signal 100.

Note that control signal 100 may be generated based on informationtransmitted by a device that is the communication partner in FIG. 1,and, alternatively, the device in FIG. 1 may include an input unit, andcontrol signal 100 may be generated based on information input from theinput unit.

FIG. 2 illustrates one example of a configuration of signal processor106 illustrated in FIG. 1. Weighting synthesizer (precoder) 203 receivesinputs of mapped signal 201A (mapped signal 105_1 in FIG. 1), mappedsignal 201B (mapped signal 105_2 in FIG. 1), and control signal 200(control signal 100 in FIG. 1), performs weighting synthesis (precoding)based on control signal 200, and outputs weighted signal 204A andweighted signal 204B. Here, mapped signal 201A is expressed as s1(t),mapped signal 201B is expressed as s2(t), weighted signal 204A isexpressed as z1(t), and weighted signal 204B is expressed as z2′(t).Note that one example oft is time (s1(t), s2(t), z1(t), and z2′(t) aredefined as complex numbers (accordingly, they may be real numbers)).

Weighting synthesizer (precoder) 203 performs the following calculation.

$\begin{matrix}\left\lbrack {{MATH}.\mspace{14mu} 1} \right\rbrack & \; \\{\begin{pmatrix}{z1(i)} \\{z\; 2^{\prime}(i)}\end{pmatrix} = {\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}} & {{Equation}\mspace{14mu}(1)}\end{matrix}$

In Equation (1), a, b, c, and d can be defined as complex numbers.Accordingly, a, b, c, and d are complex numbers (and may be realnumbers). Note that i is a symbol number.

Phase changer 205B receives inputs of weighting synthesized signal 204Band control signal 200, applies a phase change to weighting synthesizedsignal 204B based on control signal 200, and outputs phase-changedsignal 206B. Note that phase-changed signal 206B is expressed as z2(t),and z2(t) is defined as a complex number (and may be a real number).

Next, specific operations performed by phase changer 205B will bedescribed. In phase changer 205B, for example, a phase change of y(i) isapplied to z2′(i). Accordingly, z2(i) can be expressed asz2(i)=y(i)×z2′(i) (i is a symbol number (i is an integer that is greaterthan or equal to 0)).

For example, the phase change value is set as shown below (N is aninteger that is greater than or equal to 2, N is a phase changecycle)(when N is set to an odd number greater than or equal to 3, datareception quality may be improved).

$\begin{matrix}\left\lbrack {{MATH}.\mspace{14mu} 2} \right\rbrack & \; \\{{y(i)} = e^{j\frac{2x\pi xi}{N}}} & {{Equation}\mspace{14mu}(2)}\end{matrix}$

(j is an imaginary number unit). However, Equation (2) is merely anon-limiting example. Here, phase change value y(i)=e^(j×δ(i)).

Here, z1(i) and z2(i) can be expressed with the following equation.

$\begin{matrix}{\left\lbrack {{MATH}.\mspace{14mu} 3} \right\rbrack\mspace{515mu}} & \; \\\begin{matrix}{\begin{pmatrix}{z\; 1(i)} \\{z\; 2^{\prime}(i)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}{s\; 1(i)} \\{s\; 2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & e^{j \times {\delta{(i)}}}\end{pmatrix}\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}{s\; 1(i)} \\{s\; 2(i)}\end{pmatrix}}}\end{matrix} & {{Equation}\mspace{14mu}(3)}\end{matrix}$

Note that δ(i) is a real number. z1(i) and z2(i) are transmitted fromthe transmission device at the same time and using the same frequency(same frequency band).

In Equation (3), the phase change value is not limited to the value usedin Equation (2); for example, a method in which the phase is changedcyclically or regularly is conceivable.

The matrix (precoding matrix) in Equation (1) and Equation (3) is asfollows.

$\begin{matrix}{\left\lbrack {{MATH}.\mspace{14mu} 4} \right\rbrack\mspace{515mu}} & \; \\{\begin{pmatrix}a & b \\c & d\end{pmatrix} = F} & {{Equation}\mspace{14mu}(4)}\end{matrix}$

For example, using the following matrix for matrix F is conceivable.

$\begin{matrix}{\left\lbrack {{MATH}.\mspace{14mu} 5} \right\rbrack\mspace{506mu}} & \; \\{{F = \begin{pmatrix}{\beta \times e^{j0}} & {\beta \times \alpha \times e^{j0}} \\{\beta \times \alpha \times e^{j0}} & {\beta \times e^{j\pi}}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(5)} \\{\left\lbrack {{MATH}.\mspace{14mu} 6} \right\rbrack\mspace{506mu}} & \; \\{{F = {\frac{1}{\sqrt{\alpha^{2}} + 1}\begin{pmatrix}e^{j0} & {\alpha \times e^{j0}} \\{\alpha \times e^{j0}} & e^{j\pi}\end{pmatrix}}}{or}} & {{Equation}\mspace{14mu}(6)} \\{\left\lbrack {{MATH}.\mspace{14mu} 7} \right\rbrack\mspace{506mu}} & \; \\{{F = \begin{pmatrix}{\beta \times e^{j0}} & {\beta \times \alpha \times e^{j\pi}} \\{\beta \times \alpha \times e^{j0}} & {\beta \times e^{j0}}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(7)} \\{\left\lbrack {{MATH}.\mspace{14mu} 8} \right\rbrack\mspace{506mu}} & \; \\{{F = {\frac{1}{\sqrt{\alpha^{2}} + 1}\begin{pmatrix}e^{j0} & {\alpha \times e^{j\pi}} \\{\alpha \times e^{j0}} & e^{j0}\end{pmatrix}}}{or}} & {{Equation}\mspace{14mu}(8)} \\{\left\lbrack {{MATH}.\mspace{14mu} 9} \right\rbrack\mspace{506mu}} & \; \\{{F = \begin{pmatrix}{\beta \times \alpha \times e^{j0}} & {\beta \times e^{j\pi}} \\{\beta \times e^{j0}} & {\beta \times \alpha \times e^{j0}}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(9)} \\{\left\lbrack {{MATH}.\mspace{14mu} 10} \right\rbrack\mspace{490mu}} & \; \\{{F = {\frac{1}{\sqrt{\alpha^{2}} + 1}\begin{pmatrix}{\alpha \times e^{j0}} & e^{j\pi} \\e^{j0} & {\alpha \times e^{j0}}\end{pmatrix}}}{or}} & {{Equation}\mspace{14mu}(10)} \\{\left\lbrack {{MATH}.\mspace{14mu} 11} \right\rbrack\mspace{490mu}} & \; \\{{F = \begin{pmatrix}{\beta \times \alpha \times e^{j0}} & {\beta \times e^{j0}} \\{\beta \times e^{j0}} & {\beta \times \alpha \times e^{j\pi}}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(11)} \\{\left\lbrack {{MATH}.\mspace{14mu} 12} \right\rbrack\mspace{490mu}} & \; \\{F = {\frac{1}{\sqrt{\alpha^{2}} + 1}\begin{pmatrix}{\alpha \times e^{j0}} & e^{j0} \\e^{j0} & {\alpha \times e^{j\pi}}\end{pmatrix}}} & {{Equation}\mspace{14mu}(12)}\end{matrix}$

Note that in Equation (5), Equation (6), Equation (7), Equation (8),Equation (9), Equation (10), Equation (11), and Equation (12), α may bea real number and may be an imaginary number, and β may be a real numberand may be an imaginary number. However, α is not 0 (zero). β is alsonot 0 (zero).

or

$\begin{matrix}{\left\lbrack {{MATH}.\mspace{14mu} 13} \right\rbrack\mspace{490mu}} & \; \\{{F = \begin{pmatrix}{\beta \times \cos\;\theta} & {\beta \times \sin\;\theta} \\{\beta \times \sin\;\theta} & {{- \beta} \times \cos\;\theta}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(13)} \\{\left\lbrack {{MATH}.\mspace{14mu} 14} \right\rbrack\mspace{490mu}} & \; \\{{F = \begin{pmatrix}{\cos\;\theta} & {\sin\;\theta} \\{\sin\;\theta} & {{- \cos}\;\theta}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(14)} \\{\left\lbrack {{MATH}.\mspace{14mu} 15} \right\rbrack\mspace{490mu}} & \; \\{{F = \begin{pmatrix}{\beta \times \cos\;\theta} & {{- \beta} \times \sin\;\theta} \\{\beta \times \sin\;\theta} & {\beta \times \cos\;\theta}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(15)} \\{\left\lbrack {{MATH}.\mspace{14mu} 16} \right\rbrack\mspace{490mu}} & \; \\{{F = \begin{pmatrix}{\cos\;\theta} & {{- \sin}\;\theta} \\{\sin\;\theta} & {\cos\;\theta}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(16)} \\{\left\lbrack {{MATH}.\mspace{14mu} 17} \right\rbrack\mspace{490mu}} & \; \\{{F = \begin{pmatrix}{\beta \times \sin\;\theta} & {{- \beta} \times \cos\;\theta} \\{\beta \times \cos\;\theta} & {\beta \times \sin\;\theta}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(17)} \\{\left\lbrack {{MATH}.\mspace{14mu} 18} \right\rbrack\mspace{490mu}} & \; \\{{F = \begin{pmatrix}{\sin\;\theta} & {{- \cos}\;\theta} \\{\cos\;\theta} & {\sin\;\theta}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(18)} \\{\left\lbrack {{MATH}.\mspace{14mu} 19} \right\rbrack\mspace{490mu}} & \; \\{{F = \begin{pmatrix}{\beta \times \sin\;\theta} & {\beta \times \cos\;\theta} \\{\beta \times \cos\;\theta} & {{- \beta} \times \sin\;\theta}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(19)} \\{\left\lbrack {{MATH}.\mspace{14mu} 20} \right\rbrack\mspace{490mu}} & \; \\{{F = \begin{pmatrix}{\sin\;\theta} & {\cos\;\theta} \\{\cos\;\theta} & {{- s}{in}\;\theta}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(20)} \\{\left\lbrack {{MATH}.\mspace{14mu} 21} \right\rbrack\mspace{490mu}} & \; \\{{{F(i)} = \begin{pmatrix}{\beta \times e^{j{\theta_{11}{(i)}}}} & {\beta \times \alpha \times e^{j{({{\theta_{11}{(i)}} + \lambda})}}} \\{\beta \times \alpha \times e^{j{\theta_{21}{(i)}}}} & {\beta \times e^{j{({{\theta_{21}{(i)}} + \lambda + \pi})}}}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(21)} \\{\left\lbrack {{MATH}.\mspace{14mu} 22} \right\rbrack\mspace{490mu}} & \; \\{{{F(i)} = {\frac{1}{\sqrt{\alpha^{2}} + 1} = \begin{pmatrix}e^{j{\theta_{11}{(i)}}} & {\alpha \times e^{j{({{\theta_{11}{(i)}} + \lambda})}}} \\{\alpha \times e^{j{\theta_{21}{(i)}}}} & e^{j{({{\theta_{21}{(i)}} + \lambda + \pi})}}\end{pmatrix}}}{or}} & {{Equation}\mspace{14mu}(22)} \\{\left\lbrack {{MATH}.\mspace{14mu} 23} \right\rbrack\mspace{490mu}} & \; \\{{{F(i)} = \begin{pmatrix}{\beta \times \alpha \times e^{j{\theta_{21}{(i)}}}} & {\beta \times e^{j{({{\theta_{21}{(i)}} + \lambda + \pi})}}} \\{\beta \times e^{j{\theta_{11}{(i)}}}} & {\beta \times \alpha \times e^{j{({{\theta_{11}{(i)}} + \lambda})}}}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(23)} \\{\left\lbrack {{MATH}.\mspace{14mu} 24} \right\rbrack\mspace{490mu}} & \; \\{{F(i)} = {\frac{1}{\sqrt{\alpha^{2}} + 1} = \begin{pmatrix}{\alpha \times e^{j{\theta_{21}{(i)}}}} & {\alpha \times e^{j{({{\theta_{11}{(i)}} + \lambda + \pi})}}} \\e^{j{\theta_{11}{(i)}}} & {\alpha \times e^{j{({{\theta_{21}{(i)}} + \lambda})}}}\end{pmatrix}}} & {{Equation}\mspace{14mu}(24)} \\{or} & \; \\{\left\lbrack {{MATH}.\mspace{14mu} 25} \right\rbrack\mspace{490mu}} & \; \\{{{F(i)} = \begin{pmatrix}{\beta \times e^{j\theta_{11}}} & {\beta \times \alpha \times e^{j{({\theta_{11} + {\lambda{(i)}}})}}} \\{\beta \times \alpha \times e^{j\theta_{21}}} & {\beta \times \alpha \times e^{j{({\theta_{21} + {\lambda{(i)}} + \pi})}}}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(25)} \\{\left\lbrack {{MATH}.\mspace{14mu} 26} \right\rbrack\mspace{490mu}} & \; \\{{{F(i)} = {\frac{1}{\sqrt{\alpha^{2}} + 1} = \begin{pmatrix}e^{j\theta_{11}} & {\alpha \times e^{j{({\theta_{11}{\lambda{(i)}}})}}} \\{\alpha \times e^{j\theta_{21}}} & e^{j{({\theta_{21} + {\lambda{(i)}} + \pi})}}\end{pmatrix}}}{or}} & {{Equation}\mspace{14mu}(26)} \\{\left\lbrack {{MATH}.\mspace{14mu} 27} \right\rbrack\mspace{490mu}} & \; \\{{{F(i)} = \begin{pmatrix}{\beta \times \alpha \times e^{j\theta_{21}}} & {\beta \times e^{j{({\theta_{21} + {\lambda{(i)}} + \pi})}}} \\{\beta \times e^{j\theta_{11}}} & {\beta \times \alpha \times e^{j{({\theta_{11} + {\lambda{(i)}}})}}}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(27)} \\{\left\lbrack {{MATH}.\mspace{14mu} 28} \right\rbrack\mspace{490mu}} & \; \\{{{F(i)} = {\frac{1}{\sqrt{\alpha^{2}} + 1} = \begin{pmatrix}{\alpha \times e^{j\theta_{21}}} & e^{j{({{\theta_{21}{\lambda{(i)}}} + \pi})}} \\e^{j\theta_{11}} & {\alpha \times e^{j{({\theta_{11} + {\lambda{(i)}}})}}}\end{pmatrix}}}{or}} & {{Equation}\mspace{14mu}(28)} \\{\left\lbrack {{MATH}.\mspace{14mu} 29} \right\rbrack\mspace{490mu}} & \; \\{{F = \begin{pmatrix}{\beta \times e^{j\theta_{11}}} & {\beta \times \alpha \times e^{j{({\theta_{11} + \lambda})}}} \\{\beta \times \alpha \times e^{j\theta_{21}}} & {\beta \times e^{j{({\theta_{21} + \lambda + \pi})}}}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(29)} \\{\left\lbrack {{MATH}.\mspace{14mu} 30} \right\rbrack\mspace{490mu}} & \; \\{{F = {\frac{1}{\sqrt{\alpha^{2}} + 1} = \begin{pmatrix}e^{j\theta_{11}} & {\alpha \times e^{j{({\theta_{11} + \lambda})}}} \\{\alpha \times e^{j\theta_{21}}} & e^{j{({\theta_{21} + \lambda + \pi})}}\end{pmatrix}}}{or}} & {{Equation}\mspace{14mu}(30)} \\{\left\lbrack {{MATH}.\mspace{14mu} 31} \right\rbrack\mspace{490mu}} & \; \\{{F = \begin{pmatrix}{\beta \times \alpha \times e^{j\theta_{21}}} & {\beta \times e^{j{({\theta_{21} + \lambda + \pi})}}} \\{\beta \times e^{j\theta_{11}}} & {\beta \times \alpha \times e^{j{({\theta_{11} + \lambda})}}}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(31)} \\{\left\lbrack {{MATH}.\mspace{14mu} 32} \right\rbrack\mspace{490mu}} & \; \\{F = {\frac{1}{\sqrt{\alpha^{2}} + 1} = \begin{pmatrix}{\alpha \times e^{j\theta_{21}}} & e^{j{({\theta_{21} + \lambda + \pi})}} \\e^{j\theta_{21}} & {\alpha \times e^{j{({\theta_{11} + \lambda})}}}\end{pmatrix}}} & {{Equation}\mspace{14mu}(32)}\end{matrix}$

However, θ₁₁(i), θ₂₁(i), and λ(i) are functions (real numbers) of i(symbol number). λ is, for example, a fixed value (real number)(however, λ need not be a fixed value). α may be a real number, and,alternatively, may be an imaginary number. β may be a real number, and,alternatively, may be an imaginary number. However, α is not 0 (zero). βis also not 0 (zero). Moreover, θ11 and θ21 are real numbers.

Moreover, each exemplary embodiment herein can also be carried out byusing a precoding matrix other than these matrices.

or

$\begin{matrix}{\left\lbrack {{MATH}.\mspace{14mu} 33} \right\rbrack\mspace{490mu}} & \; \\{{{F(i)} = \begin{pmatrix}1 & 0 \\0 & 1\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(33)} \\{\left\lbrack {{MATH}.\mspace{14mu} 34} \right\rbrack\mspace{490mu}} & \; \\{{{F(i)} = \begin{pmatrix}\beta & 0 \\0 & \beta\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(34)} \\{\left\lbrack {{MATH}.\mspace{14mu} 35} \right\rbrack\mspace{490mu}} & \; \\{{{F(i)} = \begin{pmatrix}1 & 0 \\0 & {- 1}\end{pmatrix}}{or}} & {{Equation}\mspace{14mu}(35)} \\{\left\lbrack {{MATH}.\mspace{14mu} 36} \right\rbrack\mspace{490mu}} & \; \\{{F(i)} = \begin{pmatrix}\beta & 0 \\0 & {- \beta}\end{pmatrix}} & {{Equation}\mspace{14mu}(36)}\end{matrix}$

Note that in Equation (34) and Equation (36), β may be a real numberand, alternatively, may be an imaginary number. However, β is not 0(zero). When the precoding matrix is expressed as in Equation (33) andEquation (34), weighting synthesizer 203 in FIG. 2 outputs mapped signal201A as weighting synthesized signal 204A and mapped signal 201B asweighting synthesized signal 204B without performing signal processingon mapped signals 201A, 201B. Stated differently, weighting synthesizer203 may be omitted. Alternately, when weighting synthesizer 203 isprovided, control for whether to perform weighting synthesis or not maybe determined according to control signal 200.

Inserter 207A receives inputs of weighting synthesized signal 204A,pilot symbol signal (pa(t))(t is time)(251A), preamble signal 252,control information symbol signal 253, and control signal 200, and basedon information on the frame configuration included in control signal200, outputs baseband signal 208A based on the frame configuration.

Similarly, inserter 207B receives inputs of phase-changed signal 206B,pilot symbol signal (pb(t))(251B), preamble signal 252, controlinformation symbol signal 253, and control signal 200, and based oninformation on the frame configuration included in control signal 200,outputs baseband signal 208B based on the frame configuration.

Phase changer 209B receives inputs of baseband signal 208B and controlsignal 200, applies a phase change to baseband signal 208B based oncontrol signal 200, and outputs phase-changed signal 210B. Basebandsignal 208B is a function of symbol number i (i is an integer that isgreater than or equal to 0), and is expressed as x′(i). Then,phase-changed signal 210B (x(i)) can be expressed as x(i)=ej×ε(i)×x′(i)(j is an imaginary number unit).

Note that the operation performed by phase changer 209B may be CDD(cyclic delay diversity) or CSD (cycle shift diversity) disclosed inNPTL 2 and 3. One characteristic of phase changer 209B is that itapplies a phase change to a symbol present along the frequency axis(i.e., applies a phase change to, for example, a data symbol, a pilotsymbol, and/or a control information symbol).

In FIG. 2, phase changer 209B is included in the configuration, butphase changer 209B may be omitted from the configuration. In such cases,baseband signals 208A, 208B are the output in FIG. 2 (phase changer 209Bneed not operate).

FIG. 3 illustrates an example of a configuration of signal processor 106illustrated in FIG. 1 that differs from the configuration illustrated inFIG. 2. In FIG. 3, components that operate the same as in FIG. 2 sharelike reference marks. Note that duplicate description of components thatperform the same operations as in FIG. 2 will be omitted.

Coefficient multiplier 301A receives inputs of mapped signal 201A(s1(i)) and control signal 200, and based on control signal 200,multiplies mapped signal 201A (s1(i)) by a coefficient, and outputscoefficient multiplied signal 302A. Note that when the coefficient isexpressed as u, coefficient multiplied signal 302A is expressed asu×s1(i) (u may be a real number and, alternatively, may be a complexnumber). However, when u=1, coefficient multiplier 301A outputs mappedsignal 201A (s1(i)) as coefficient multiplied signal 302A withoutmultiplying mapped signal 201A (s1(i)) by the coefficient.

Similarly, coefficient multiplier 301B receives inputs of mapped signal201B (s2(i)) and control signal 200, and based on control signal 200,multiplies mapped signal 201B (s2(i)) by a coefficient, and outputscoefficient multiplied signal 302B. Note that when the coefficient isexpressed as v, coefficient multiplied signal 302B is expressed asv×s2(i) (v may be a real number and, alternatively, may be a complexnumber). However, when v=1, coefficient multiplier 301B outputs mappedsignal 201B (s2(i)) as coefficient multiplied signal 302B withoutmultiplying mapped signal 201B (s2(i)) by the coefficient.

Accordingly, weighting synthesized signal 204A (z1(i)) and phase-changedsignal 206B (z2(i)) can be expressed with the following equation.

$\begin{matrix}{\left\lbrack {{MATH}.\mspace{14mu} 37} \right\rbrack\mspace{490mu}} & \; \\{\begin{pmatrix}{z\; 1(i)} \\{z\; 2(i)}\end{pmatrix} = {{\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}{F\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}}\begin{pmatrix}{s\; 1(i)} \\{s\; 2(i)}\end{pmatrix}} = {{\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}{s\; 1(i)} \\{s\; 2(i)}\end{pmatrix}} = {\begin{pmatrix}1 & 0 \\0 & e^{j \times {\delta{(i)}}}\end{pmatrix}\begin{pmatrix}a & b \\c & d\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}{s\; 1(i)} \\{s\; 2(i)}\end{pmatrix}}}}} & {{Equation}\mspace{14mu}(37)}\end{matrix}$

Note that the example of the (precoding) matrix F is as previouslydescribed (for example, see Equation (5) through Equation (36)), and theexample of phase change value y(i) is as indicated in Equation (2), butthe (precoding) matrix F and phase change value y(i) are not limited tothese examples.

Next, “the (precoding) matrix F and phase change value y(i) when themodulation scheme for mapped signal 201A (s1(i)) is QPSK (quadraturephase shift keying) and the modulation scheme used for mapped signal201B (s2(i)) is 16QAM (QAM: quadrature amplitude modulation)” used inthe description of the present invention will be described.

Note that here, the average (transmission) power of mapped signal 201Aand the average (transmission) power of mapped signal 201B are the same.

In such cases, by obtaining weighting synthesized signal 204A (z1(i))and phase-changed signal 206B (z2(i)) as illustrated in Equation (38)through Equation (45), in the reception device that receives themodulated signal transmitted by the transmission device illustrated inFIG. 1, an advantageous effect that data reception quality is improvedcan be achieved.

$\begin{matrix}{\left\lbrack {{MATH}.\mspace{14mu} 38} \right\rbrack\mspace{490mu}} & \; \\\begin{matrix}{\begin{pmatrix}{z\; 1(i)} \\{z\; 2(i)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}{F\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}}\begin{pmatrix}{s\; 1(i)} \\{s\; 2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}\begin{pmatrix}{\beta \times \cos\;\theta} & {{- \beta} \times \sin\;\theta} \\{\beta \times \sin\;\theta} & {\beta \times \cos\;\theta}\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}{s\; 1(i)} \\{s\; 2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & e^{j \times {\delta{(i)}}}\end{pmatrix}\begin{pmatrix}{\beta \times \cos\frac{\pi}{4}} & {{- \beta} \times \sin\frac{\pi}{4}} \\{\beta \times \sin\frac{\pi}{4}} & {\beta \times \cos\frac{\pi}{4}}\end{pmatrix}\begin{pmatrix}\sqrt{\frac{2}{3}} & 0 \\0 & \sqrt{\frac{4}{3}}\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}}\end{matrix} & {{Equation}\mspace{14mu}(38)} \\{\left\lbrack {{MATH}.\mspace{14mu} 39} \right\rbrack\mspace{490mu}} & \; \\\begin{matrix}{\begin{pmatrix}{z\; 1(i)} \\{z\; 2(i)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}{F\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}}\begin{pmatrix}{s\; 1(i)} \\{s\; 2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}\begin{pmatrix}{\beta \times \cos\;\theta} & {{- \beta} \times \sin\;\theta} \\{\beta \times \sin\;\theta} & {\beta \times \cos\;\theta}\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}{s\; 1(i)} \\{s\; 2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & e^{j \times {\delta{(i)}}}\end{pmatrix}\begin{pmatrix}{\beta \times \cos\frac{\pi}{4}} & {{- \beta} \times \sin\frac{\pi}{4}} \\{\beta \times \sin\frac{\pi}{4}} & {\beta \times \cos\frac{\pi}{4}}\end{pmatrix}\begin{pmatrix}{\alpha \times \sqrt{\frac{2}{3}}} & 0 \\0 & {\alpha \times \sqrt{\frac{4}{3}}}\end{pmatrix}\begin{pmatrix}{s\; 1(i)} \\{s\; 2(i)}\end{pmatrix}}}\end{matrix} & {{Equation}\mspace{14mu}(39)} \\{\left\lbrack {{MATH}.\mspace{14mu} 40} \right\rbrack\mspace{490mu}} & \; \\\begin{matrix}{\begin{pmatrix}{z1(i)} \\{z2(i)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}{F\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}\begin{pmatrix}{\cos\;\theta} & {{- \sin}\;\theta} \\{\sin\;\theta} & {\cos\;\theta}\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & e^{j \times {\delta{(i)}}}\end{pmatrix}\begin{pmatrix}{\cos\frac{\pi}{4}} & {{- \sin}\frac{\pi}{4}} \\{\sin\frac{\pi}{4}} & {\cos\frac{\pi}{4}}\end{pmatrix}\begin{pmatrix}\sqrt{\frac{2}{3}} & 0 \\0 & \sqrt{\frac{4}{3}}\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}}\end{matrix} & {{Equation}\mspace{14mu}(40)} \\{\left\lbrack {{MATH}.\mspace{14mu} 41} \right\rbrack\mspace{490mu}} & \; \\\begin{matrix}{\begin{pmatrix}{z1(i)} \\{z2(i)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}{F\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}\begin{pmatrix}{\cos\;\theta} & {{- \sin}\;\theta} \\{\sin\;\theta} & {\cos\;\theta}\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & e^{j \times {\delta{(i)}}}\end{pmatrix}\begin{pmatrix}{\cos\frac{\pi}{4}} & {{- \sin}\frac{\pi}{4}} \\{\sin\frac{\pi}{4}} & {\cos\frac{\pi}{4}}\end{pmatrix}\begin{pmatrix}{\alpha \times \sqrt{\frac{2}{3}}} & 0 \\0 & {\alpha \times \sqrt{\frac{4}{3}}}\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}}\end{matrix} & {{Equation}\mspace{14mu}(41)} \\{\left\lbrack {{MATH}.\mspace{14mu} 42} \right\rbrack\mspace{490mu}} & \; \\\begin{matrix}{\begin{pmatrix}{z1(i)} \\{z2(i)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}{F\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}\begin{pmatrix}{\beta \times \cos\;\theta} & {\beta \times \sin\;\theta} \\{\beta \times \sin\;\theta} & {{- \beta} \times \cos\;\theta}\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & e^{j \times {\delta{(i)}}}\end{pmatrix}\begin{pmatrix}{\beta \times \cos\frac{\pi}{4}} & {{- \beta} \times \sin\frac{\pi}{4}} \\{\beta \times \sin\frac{\pi}{4}} & {\beta \times \cos\frac{\pi}{4}}\end{pmatrix}\begin{pmatrix}\sqrt{\frac{2}{3}} & 0 \\0 & \sqrt{\frac{4}{3}}\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}}\end{matrix} & {{Equation}\mspace{14mu}(42)} \\{\left\lbrack {{MATH}.\mspace{14mu} 43} \right\rbrack\mspace{490mu}} & \; \\\begin{matrix}{\begin{pmatrix}{z1(i)} \\{z2(i)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}{F\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}\begin{pmatrix}{\beta \times \cos\;\theta} & {\beta \times \sin\;\theta} \\{\beta \times \sin\;\theta} & {{- \beta} \times \cos\;\theta}\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & e^{j \times {\delta{(i)}}}\end{pmatrix}\begin{pmatrix}{\beta \times \cos\frac{\pi}{4}} & {\beta \times \sin\frac{\pi}{4}} \\{\beta \times \sin\frac{\pi}{4}} & {{- \beta} \times \cos\frac{\pi}{4}}\end{pmatrix}\begin{pmatrix}{\alpha \times \sqrt{\frac{2}{3}}} & 0 \\0 & {\alpha \times \sqrt{\frac{4}{3}}}\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}}\end{matrix} & {{Equation}\mspace{14mu}(43)} \\{\left\lbrack {{MATH}.\mspace{14mu} 44} \right\rbrack\mspace{490mu}} & \; \\\begin{matrix}{\begin{pmatrix}{z1(i)} \\{z2(i)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}{F\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}\begin{pmatrix}{\cos\;\theta} & {\sin\;\theta} \\{\sin\;\theta} & {{- \cos}\;\theta}\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & e^{j \times {\delta{(i)}}}\end{pmatrix}\begin{pmatrix}{\cos\frac{\pi}{4}} & {\sin\frac{\pi}{4}} \\{\sin\frac{\pi}{4}} & {{- \cos}\frac{\pi}{4}}\end{pmatrix}\begin{pmatrix}\sqrt{\frac{2}{3}} & 0 \\0 & \sqrt{\frac{4}{3}}\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}}\end{matrix} & {{Equation}\mspace{14mu}(44)} \\{\left\lbrack {{MATH}.\mspace{14mu} 45} \right\rbrack\mspace{490mu}} & \; \\\begin{matrix}{\begin{pmatrix}{z1(i)} \\{z2(i)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}{F\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}\begin{pmatrix}{\cos\;\theta} & {\sin\;\theta} \\{\sin\;\theta} & {{- \cos}\;\theta}\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}} \\{= {\begin{pmatrix}1 & 0 \\0 & e^{j \times {\delta{(i)}}}\end{pmatrix}\begin{pmatrix}{\cos\frac{\pi}{4}} & {\sin\frac{\pi}{4}} \\{\sin\frac{\pi}{4}} & {{- \cos}\frac{\pi}{4}}\end{pmatrix}\begin{pmatrix}{\alpha \times \sqrt{\frac{2}{3}}} & 0 \\0 & {\alpha \times \sqrt{\frac{4}{3}}}\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}}\end{matrix} & {{Equation}\mspace{14mu}(45)}\end{matrix}$

Note that in Equation (38) through Equation (45), a and β may be realnumbers and, alternatively, may be imaginary numbers.

Next, the characteristic points of Equation (38) through Equation (45)will be described.

In Equation (38) through Equation (45), 0 is set to π/4 radians (45degrees). The average (transmission) power of coefficient multipliedsignal 302A and the average (transmission) power of coefficientmultiplied signal 302B are different, but by setting θ to π/4 radians(45 degrees), the average (transmission) power of weighting synthesizedsignal 204A (z1(i)) and the average (transmission) power ofphase-changed signal 206B (z2(i)) can be made to be the same, so whenthe transmission rules stipulate a condition that the averagetransmission power of each modulated signal transmitted from theantennas be the same, it is necessary to set θ to π/4 radians (45degrees). Note that, here, θ is set to π/4 radians (45 degrees), but θmay be set to any one of: π/4 radians (45 degrees); (3×π)/4 radians (135degrees); (5×π)/4 radians (225 degrees); and (7×π)/4 radians (315degrees).

Moreover, the coefficients u, v are set as illustrated in Equation (38)through Equation (45).

Note that symbols (for example, z1(i), z2(i)) are described as beinggenerated using the methods exemplified in FIG. 1, FIG. 2, FIG. 3, andEquation (1) through Equation (45). In such cases, the generated symbolsmay be arranged along the time axis. When a multi-carrier scheme such asOFDM (orthogonal frequency division multiplexing) is used, the generatedsymbols may be arranged along the frequency axis and may be arrangedalong the time and frequency axes. Moreover, the generated symbols maybe interleaved (i.e., rearranged) and arranged along the time axis,along the frequency axis, and along the time and frequency axes.However, z1(i) and z2(i), which are both symbol number i, aretransmitted from the transmission device at the same time and using thesame frequency (same frequency band).

FIG. 4 shows the capacity for each SNR (signal-to-noise power ratio). InFIG. 4, PQPSK/(PQPSK+P16QAM) is represented on the horizontal axis, andcapacity is represented on the vertical axis. PQPSK is the average(transmission) power of QPSK, and P16QAM is the average (transmission)power of 16QAM (note that the channel model in the graph is an AWGN(additive white Gaussian noise) environment). As can be seen from theresults, by using the settings illustrated in Equation (38) throughEquation (45), the reception device can achieve an advantageous effectof good data reception quality.

The transmission device illustrated in FIG. 1 switches the transmissionmethod of the modulated signal based on information on the transmissionmethod included in control signal 100. The transmission deviceillustrated in FIG. 1 can select the following transmission methods.

Transmission Method #1:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is BPSK (binary phase shift keying) (or π/2 shiftBPSK) (however, the single stream modulated signal may be transmittedusing a single antenna and, alternatively, transmitted using a pluralityof antennas).

Transmission Method #2:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is QPSK (quadrature phase shift keying) (or π/2 shiftQPSK) (however, the single stream modulated signal may be transmittedusing a single antenna and, alternatively, transmitted using a pluralityof antennas).

Transmission Method #3:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is 16QAM (or π/2 shift 16QAM) (or a modulation schemein which 16 signal points are in the in-phase I-quadrature Q plane, suchas 16APSK (APSK: amplitude phase shift keying) (a shift may beperformed)) (however, the single stream modulated signal may betransmitted using a single antenna and, alternatively, transmitted usinga plurality of antennas).

Transmission Method #4:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is 64QAM (or π/2 shift 64QAM) (or a modulation schemein which 64 signal points are in the in-phase I-quadrature Q plane, suchas 64APSK (APSK: amplitude phase shift keying) (a shift may beperformed)) (however, the single stream modulated signal may betransmitted using a single antenna and, alternatively, transmitted usinga plurality of antennas).

Transmission Method #5:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is BPSK (or π/2 shift BPSK), and themodulation scheme of s2(i) is BPSK (or π/2 shift BPSK). Here, twomodulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas.

Transmission Method #6:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is QPSK (or π/2 shift QPSK). Here, twomodulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas.

Transmission Method #7:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas.

Transmission Method #8:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas.

Transmission Method #9:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 64APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas.

Here, based on FIG. 2 and FIG. 3, precoding (weighted synthesis) and aphase change are performed (phase changer 205B need not perform a phasechange), and any one of the (precoding) matrices in Equation (13)through Equation (20) is used as the precoding matrix. However, θ inEquation (13) through Equation (20) is greater than or equal to 0radians and less than a radians (θ radians≤θ<2π radians).

With this, the following is satisfied.

Transmission Method #1:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 2.

Transmission Method #2:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 4.

Transmission Method #3:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 16.

Transmission Method #4:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 64.

Transmission Method #5:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 2 and less than or equalto 4. However, when θ=0 radians in Equation (13) through Equation (20),the number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 2.

Transmission Method #6:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 4 and less than or equalto 16. However, when θ=0 radians in Equation (13) through Equation (20),the number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 4.

Transmission Method #7:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 4 and less than or equalto 64. However, when θ=0 radians in Equation (13) through Equation (20),the number of signal points in the in-phase I-quadrature Q plane of thefirst transmission signal is 4, and the number of signal points in thein-phase I-quadrature Q plane of the second transmission signal is 16.

Transmission Method #8:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 16 and less than orequal to 256. However, when θ=0 radians in Equation (13) throughEquation (20), the number of signal points in the in-phase I-quadratureQ plane of the transmission signal is 16.

Transmission Method #9:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 64 and less than orequal to 4096. However, when θ=0 radians in Equation (13) throughEquation (20), the number of signal points in the in-phase I-quadratureQ plane of the transmission signal is 64.

As described above, the maximum number of signal points when thetransmission device illustrated in FIG. 1 transmits the single streammodulated signal is 64.

When the influence of phase noise in RF (radio frequency) unit includedin radio units 107_A, 107_B in the transmission device illustrated inFIG. 1 and the influence of non-linear distortion in the transmissionpower amplifier included in radio units 107_A, 107_B are taken intoconsideration, a modulation scheme in which the PAPR (peak-to-averagepower ratio) is low and a modulation scheme having a signal pointarrangement that yields little phase noise influence are preferablyused. Taking these into consideration, it is preferable that the numberof signal points in the in-phase I-quadrature Q plane of thetransmission signal (modulated signal) be reduced. As described above,when the transmission device can select from a plurality of transmissionmethods, since, by minimizing the number of signal points in thein-phase I-quadrature Q plane in the transmission method having thelargest number of signal points in the in-phase I-quadrature Q plane,influence of phase noise in the RF unit can be inhibited and influenceof non-linear distortion in the transmission power amplifier can beinhibited in the transmission device, in the reception device thatreceives the modulated signal transmitted by the transmission deviceillustrated in FIG. 1, it is possible to achieve an advantageous effectthat the data reception quality is improved. Moreover, when thetransmission device illustrated in FIG. 1 transmits a modulated signalcharacterized by low phase noise influence in the RF unit and lownon-linear distortion in the transmission power amplifier, anadvantageous effect that the scale of the circuits for the RF unit andtransmission power amplifier in the transmission device can be reducedcan be achieved (when the PAPR greatly varies from modulation scheme tomodulation scheme, for example, an RF unit and transmission poweramplification unit need to be provided for each modulation scheme,thereby increasing the scale of circuitry).

As described above, the maximum number of signal points when thetransmission device illustrated in FIG. 1 transmits the single streammodulated signal is 64. Accordingly, if the maximum number of signalpoints when the transmission device illustrated in FIG. 1 transmits twostreams of modulated signals can be kept to 64, the above-describedadvantageous effects can be achieved.

On the other hand, when the transmission device illustrated in FIG. 1transmits two streams of modulated signals, and the s1(i) signal istransmitted from a plurality of antennas and the s2(i) signal istransmitted from a plurality of antennas, the advantageous effects oftransmit diversity are achieved, so the reception device that receivesthe modulated signal transmitted by the transmission device illustratedin FIG. 1 can achieve the advantageous effect that data receptionquality is improved. However, in order to achieve this advantageouseffect, it is important that the modulated signal transmitted by thetransmission device illustrated in FIG. 1 exhibit a small phase noiseinfluence in the RF unit and a small non-linear distortion influence inthe transmission power amplifier.

In view of this, consider a first or second selection method.

First Selection Method:

The transmission device illustrated in FIG. 1 switches the transmissionmethod of the modulated signal based on information on the transmissionmethod included in control signal 100. Here, the transmission deviceillustrated in FIG. 1 can select the following transmission methods.

Transmission Method #1-1:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is BPSK (or π/2 shift BPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #1-2:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is QPSK (or π/2 shift QPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #1-3:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or a modulation scheme inwhich 16 signal points are in the in-phase I-quadrature Q plane, such as16APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #1-4:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or a modulation scheme inwhich 64 signal points are in the in-phase I-quadrature Q plane, such as64APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #1-5:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is BPSK (or π/2 shift BPSK), and themodulation scheme of s2(i) is BPSK (or π/2 shift BPSK). Here, twomodulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Transmission Method #1-6:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is QPSK (or π/2 shift QPSK). Here, twomodulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Transmission Method #1-7:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)) (when θ=π/4 radians (45degrees), the average transmission power of the modulated signalstransmitted from the antennas is equal).

Transmission Method #1-8:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ=0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Transmission Method #1-9:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 64APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ=0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Note that in the first selection method, the transmission method neednot correspond to all transmission methods from transmission method #1-1to transmission method #1-9. For example, in the first selection method,the transmission method may correspond to one or more transmissionmethod from among the following three transmission methods: transmissionmethod #1-5, transmission method #1-6, and transmission method #1-7. Inthe first transmission method, the transmission method may correspond toone or more transmission method from among the following twotransmission methods: transmission method #1-8 and transmission method#1-9.

In the first selection method, the transmission method need notcorrespond to transmission method #1-1 (in the first selection method,the transmission method need not include transmission method #1-1 in thetransmission method selection candidates in the transmission deviceillustrated in FIG. 1).

The first selection method may include a transmission method other thanthose from transmission method #1-1 to transmission method #1-9.

Here, the following is satisfied.

Transmission Method #1-1:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 2.

Transmission Method #1-2:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 4.

Transmission Method #1-3:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 16.

Transmission Method #1-4:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 64.

Transmission Method #1-5:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 2 and less than or equal to 4. Theadvantageous effect of transmit diversity is achievable.

Transmission Method #1-6:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 4 and less than or equal to 16. Theadvantageous effect of transmit diversity is achievable.

Transmission Method #1-7:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 4 and less than or equal to 64. Theadvantageous effect of transmit diversity is achievable.

Transmission Method #1-8:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 16.

Transmission Method #1-9:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 64.

Since the above-described characteristics are achieved, by using thefirst selection method, in the transmission device illustrated in FIG.1, influence of phase noise in RF unit and influence of non-lineardistortion in transmission power amplifier can be reduced, andadvantageous effect of transmit diversity is achievable in transmissionmethod #1-5 through transmission method #1-7. Accordingly, in thereception device that receives the modulated signal transmitted by thetransmission device illustrated in FIG. 1, it is possible to achieve anadvantageous effect of improvement in data reception quality.

Second Selection Method: Transmission Method #2-1:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is BPSK (or π/2 shift BPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #2-2:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is QPSK (or π/2 shift QPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #2-3:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or a modulation scheme inwhich 16 signal points are in the in-phase I-quadrature Q plane, such as16APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #2-4:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or a modulation scheme inwhich 64 signal points are in the in-phase I-quadrature Q plane, such as64APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #2-5:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is BPSK (or π/2 shift BPSK), and themodulation scheme of s2(i) is BPSK (or π/2 shift BPSK). Here, twomodulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)).

Next, precoding processing will be described.

In the transmission device illustrated in FIG. 1, a plurality ofprecoding matrices expressed by any of Equation (13) through Equation(20) are provided for performing precoding processing. For example, N (Nis an integer that is greater than or equal to 2) precoding matrices areprepared. Here, the N precoding matrices are referred to as i-th matrix(i is an integer that is greater than or equal to 1 and less than orequal to N) (the i-th matrix may be expressed as any one of the matrixesin Equation (13) through Equation (20)).

Based on control signal 200, weighting synthesizer 203 illustrated inFIG. 2, FIG. 3 uses one matrix specified by control signal 200 fromamong the N matrices from the first matrix to the N-th matrix, andperforms precoding.

Note that the N matrices include at least one precoding matrix thatsatisfies any one of Equation (13) through Equation (20) in which θ=0,and include at least one precoding matrix that satisfies any one ofEquation (13) through Equation (20) in which θ≠0.

Transmission Method #2-6:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is QPSK (or π/2 shift QPSK). Here, twomodulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)).

Next, precoding processing will be described.

In the transmission device illustrated in FIG. 1, a plurality ofprecoding matrices expressed by any of Equation (13) through Equation(20) are provided for performing precoding processing. For example, N (Nis an integer that is greater than or equal to 2) precoding matrices areprepared. Here, the N precoding matrices are referred to as i-th matrix(i is an integer that is greater than or equal to 1 and less than orequal to N) (the i-th matrix may be expressed as any one of the matrixesin Equation (13) through Equation (20)).

Based on control signal 200, weighting synthesizer 203 illustrated inFIG. 2, FIG. 3 uses one matrix specified by control signal 200 fromamong the N matrices from the first matrix to the N-th matrix, andperforms precoding.

Note that the N matrices include at least one precoding matrix thatsatisfies any one of Equation (13) through Equation (20) in which θ=0,and include at least one precoding matrix that satisfies any one ofEquation (13) through Equation (20) in which θ≠0.

Transmission Method #2-7:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)) (when θ=π/4 radians (45degrees), the average transmission power of the modulated signalstransmitted from the antennas is equal).

Transmission Method #2-8:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ=0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Transmission Method #2-9:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 64APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ=0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Note that in the second selection method, the transmission method neednot correspond to all transmission methods from transmission method #2-1to transmission method #2-9. For example, in the second selectionmethod, the transmission method may correspond to one or moretransmission method from among the following three transmission methods:transmission method #2-5, transmission method #2-6, and transmissionmethod #2-7. In the second transmission method, the transmission methodmay correspond to one or more transmission method from among thefollowing two transmission methods: transmission method #2-8 andtransmission method #2-9.

In the second selection method, the transmission method need notcorrespond to transmission method #2-1 (in the second selection method,the transmission method need not include transmission method #2-1 in thetransmission method selection candidates in the transmission deviceillustrated in FIG. 1).

The second selection method may include a transmission method other thanthose from transmission method #2-1 to transmission method #2-9.

Here, the following is satisfied.

Transmission Method #2-1:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 2.

Transmission Method #2-2:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 4.

Transmission Method #2-3:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 16.

Transmission Method #2-4:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 64.

Transmission Method #2-5:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 2 and less than or equalto 4. There are cases in which the advantageous effect of transmitdiversity is achievable.

Transmission Method #2-6:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 4 and less than or equalto 16. There are cases in which the advantageous effect of transmitdiversity is achievable.

Transmission Method #2-7:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 4 and less than or equal to 64. Theadvantageous effect of transmit diversity is achievable.

Transmission Method #2-8:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 16.

Transmission Method #2-9:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 64.

Since the above-described characteristics are achieved, by using thesecond selection method, in the transmission device illustrated in FIG.1, influence of phase noise in RF unit and influence of non-lineardistortion in transmission power amplifier can be reduced, and there arecases in which the advantageous effect of transmit diversity isachievable in transmission method #2-5 through transmission method #2-7.Accordingly, in the reception device that receives the modulated signaltransmitted by the transmission device illustrated in FIG. 1, it ispossible to achieve an advantageous effect of improvement in datareception quality.

Moreover, a third selection method, which is a combination of the firstselection method and the second selection method, may be used.

Third Selection Method:

The transmission device illustrated in FIG. 1 switches the transmissionmethod of the modulated signal based on information on the transmissionmethod included in control signal 100. Here, the transmission methodillustrated in FIG. 1 can select the following transmission methods.

Transmission Method #3-1:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is BPSK (or π/2 shift BPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #3-2:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is QPSK (or π/2 shift QPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #3-3:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or a modulation scheme inwhich 16 signal points are in the in-phase I-quadrature Q plane, such as16APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #3-4:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or a modulation scheme inwhich 64 signal points are in the in-phase I-quadrature Q plane, such as64APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #3-5:

Either one of transmission method #1-5 or transmission method #2-5.

Transmission Method #3-6:

Either one of transmission method #1-6 or transmission method #2-6.

Transmission Method #3-7:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Transmission Method #3-8:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ=0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Transmission Method #3-9:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 64APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ=0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Note that in the third selection method, the transmission method neednot correspond to all transmission methods from transmission method #3-1to transmission method #3-9. For example, in the third selection method,the transmission method may correspond to one or more transmissionmethod from among the following three transmission methods: transmissionmethod #3-5, transmission method #3-6, and transmission method #3-7. Inthe third transmission method, the transmission method may correspond toone or more transmission method from among the following twotransmission methods: transmission method #3-8 and transmission method#3-9.

In the third selection method, the transmission method need notcorrespond to transmission method #3-1 (in the third selection method,the transmission method need not include transmission method #3-1 in thetransmission method selection candidates in the transmission deviceillustrated in FIG. 1).

The third selection method may include a transmission method other thanthose from transmission method #3-1 to transmission method #3-9.

Since the above-described characteristics are achieved, by using thethird selection method, in the transmission device illustrated in FIG.1, influence of phase noise in RF unit and influence of non-lineardistortion in transmission power amplifier can be reduced, and there arecases in which the advantageous effect of transmit diversity isachievable in transmission method #3-5 through transmission method #3-7.Accordingly, in the reception device that receives the modulated signaltransmitted by the transmission device illustrated in FIG. 1, it ispossible to achieve an advantageous effect of improvement in datareception quality.

FIG. 5 illustrates one example of a configuration of radio units 107_Aand 107_B illustrated in FIG. 1 when the transmission device illustratedin FIG. 1 has an OFDM (orthogonal frequency division multiplexing)configuration. Serial-parallel converter 502 receives inputs of signal501 and control signal 500 (control signal 100 in FIG. 1), applies aserial-parallel conversion based on control signal 500, and outputsserial-parallel converted signal 503.

Inverse Fourier transform unit 504 receives inputs of serial-parallelconverted signal 503 and control signal 500, and based on control signal500, applies, as one example of an inverse Fourier transform, an IFFT(inverse fast Fourier transform), and outputs inverse Fouriertransformed signal 505.

Processor 506 receives inputs of inverse Fourier transformed signal 505and control signal 500, applies processing such as frequency conversionand amplification based on control signal 500, and outputs modulatedsignal 507.

(For example, when signal 501 is signal-processed signal 106_Aillustrated in FIG. 1, modulated signal 507 corresponds to transmissionsignal 108_A in FIG. 1. Moreover, when signal 501 is signal-processedsignal 106_B illustrated in FIG. 1, modulated signal 507 corresponds totransmission signal 108_B in FIG. 1.)

FIG. 6 illustrates a frame configuration of transmission signal 108_Aillustrated in FIG. 1. In FIG. 6, frequency (carriers) is (are)represented on the horizontal axis and time is represented on thevertical axis. Since a multi-carrier transmission method such as OFDM isused, symbols are present in the carrier direction. In FIG. 6, symbolsfrom carriers 1 to 36 are shown. Moreover, in FIG. 6, symbols for time$1 through time $11 are shown.

In FIG. 6, 601 is a pilot symbol (pilot signal 251A (pa(t) in FIG. 2,FIG. 3)), 602 is a data symbol, and 603 is an other symbol. Here, apilot symbol is, for example, a PSK (phase shift keying) symbol, and isa symbol for the reception device that receives this frame to performchannel estimation (propagation path fluctuation estimation), frequencyoffset estimation, and phase fluctuation estimation. For example, thetransmission device illustrated in FIG. 1 and the reception device thatreceives the frame illustrated in FIG. 6 may share the transmissionmethod of the pilot symbol.

Note that mapped signal 201A (mapped signal 105_1 in FIG. 1) is referredto as “stream #1” and mapped signal 201B (mapped signal 105_2 in FIG. 1)is referred to as “stream #2.” Note that this also applied to subsequentdescriptions.

Data symbol 602 is a symbol that corresponds to a data symbol includedin baseband signal 208A generated in the signal processing illustratedin FIG. 2, FIG. 3. Accordingly, data symbol 602 satisfies “a symbolincluding both the symbol “stream #1” and the symbol “stream #2””, “thesymbol “stream #1””, or “the symbol “stream #2””, as determined by theconfiguration of the precoding matrix used by weighting synthesizer 203(in other words, data symbol 602 corresponds to weighting synthesizedsignal 204A (z1(i))).

Other symbols 603 are symbols corresponding to preamble signal 252 andcontrol information symbol signal 253 illustrated in FIG. 2, FIG. 3(however, the other symbols may include symbols other than a preamble orcontrol information symbol). Here, a preamble may transmit data (controldata), and may be configured as, for example, a symbol for signaldetection, a signal for performing frequency and time synchronization,or a symbol for performing channel estimation (a symbol for performingpropagation path fluctuation estimation). The control information symbolis a symbol including control information for the reception device thatreceived the frame in FIG. 6 to demodulate and decode a data symbol.

For example, carriers $1 to 36 from time $1 to time 4 in FIG. 6 areother symbols 603. Then, at time $5, carrier 1 through carrier 11 aredata symbols 602. Thereafter, at time $5, carrier 12 is pilot symbol601, at time $5, carriers 13 to 23 are data symbols 602, at time $5,carrier 24 is pilot symbol 601 . . . at time $6, carriers 1 and 2 aredata symbols 602, at time $6, carrier 3 is pilot symbol 601 . . . attime $11, carrier 30 is pilot symbol 601, at time $11, carriers 31 to 36are data symbols 602.

FIG. 7 illustrates a frame configuration of transmission signal 108_Billustrated in FIG. 1. In FIG. 7, frequency (carriers) is (are)represented on the horizontal axis and time is represented on thevertical axis. Since a multi-carrier transmission method such as OFDM isused, symbols are present in the carrier direction. In FIG. 7, symbolsfrom carriers 1 to 36 are shown. Moreover, in FIG. 7, symbols for time$1 through time $11 are shown.

In FIG. 7, 701 is a pilot symbol (pilot signal 251B (pb(t) in FIG. 2,FIG. 3)), 702 is a data symbol, and 703 is an other symbol. Here, apilot symbol is, for example, a PSK symbol, and is a symbol for thereception device that receives this frame to perform channel estimation(propagation path fluctuation estimation), frequency offset estimation,and phase fluctuation estimation. For example, the transmission deviceillustrated in FIG. 1 and the reception device that receives the frameillustrated in FIG. 7 may share the transmission method of the pilotsymbol.

Data symbol 702 is a symbol that corresponds to a data symbol includedin baseband signal 208B generated in the signal processing illustratedin FIG. 2, FIG. 3. Accordingly, data symbol 702 satisfies “a symbolincluding both the symbol “stream #1” and the symbol “stream #2””, “thesymbol “stream #1””, or “the symbol “stream #2””, as determined by theconfiguration of the precoding matrix used by weighting synthesizer 203(in other words, data symbol 702 corresponds to phase-changed signal206B (z2(i))).

Other symbols 703 are symbols corresponding to preamble signal 252 andcontrol information symbol signal 253 illustrated in FIG. 2, FIG. 3(however, the other symbols may include symbols other than a preamble orcontrol information symbol). Here, a preamble may transmit data (controldata), and is configured as, for example, a symbol for signal detection,a signal for performing frequency and time synchronization, or a symbolfor performing channel estimation (a symbol for performing propagationpath fluctuation estimation). The control information symbol is a symbolincluding control information for the reception device that received theframe in FIG. 7 to demodulate and decode a data symbol.

For example, carriers 1 to 36 from time $1 to time 4 in FIG. 7 are othersymbols 703. Then, at time $5, carrier 1 through carrier 11 are datasymbols 702. Thereafter, at time $5, carrier 12 is pilot symbol 701, attime $5, carriers 13 to 23 are data symbols 702, at time $5, carrier 24is pilot symbol 701 . . . at time $6, carriers 1 and 2 are data symbols702, at time $6, carrier 3 is pilot symbol 701 . . . at time $11,carrier 30 is pilot symbol 701, at time $11, carriers 31 to 36 are datasymbols 702.

When a symbol is present in carrier A at time $B in FIG. 6 and a symbolis present in carrier A at time $B in FIG. 7, the symbol in carrier A attime $B in FIG. 6 and the symbol in carrier A at time $B in FIG. 5 aretransmitted at the same time and same frequency. Note that the frameconfiguration is not limited to the configurations illustrated in FIG. 6and FIG. 7; FIG. 6 and FIG. 7 are mere examples of frame configurations.

The other symbols in FIG. 6 and FIG. 7 are symbols corresponding to“preamble signal 252 and control information symbol signal 253 in FIG.2, FIG. 3.” Accordingly, when an other symbol 603 in FIG. 6 at the sametime and same frequency (same carrier) as an other symbol 703 in FIG. 7transmits control information, it transmits the same data (the samecontrol information).

Note that this is under the assumption that the frame of FIG. 6 and theframe of FIG. 7 are received at the same time by the reception device,but even when the frame of FIG. 6 or the frame of FIG. 7 has beenreceived, the reception device can obtain the data transmitted by thetransmission device.

FIG. 8 illustrates one example of components relating to controlinformation generation for generating control information symbol signal253 illustrated in FIG. 2, FIG. 3.

Control information mapper 802 receives inputs of data 801 related tocontrol information and control signal 800, maps data 801 related tocontrol information in using a modulation scheme based on control signal800, and outputs control information mapped signal 803. Note thatcontrol information mapped signal 803 corresponds to control informationsymbol signal 253 in FIG. 2, FIG. 3.

FIG. 9 illustrates one example of a configuration of antenna unit #A(109_A), antenna #B (109_B) illustrated in FIG. 1 (antenna unit #A(109_A) and antenna unit #B (109_B) are exemplified as including aplurality of antennas). Splitter 902 receives an input of transmissionsignal 901, performs splitting, and outputs transmission signals 903_1,903_2, 903_3, and 903_4.

Multiplier 904_1 receives inputs of transmission signal 903_1 andcontrol signal 900, and based on the multiplication coefficient includedin control signal 900, multiplies a multiplication coefficient withtransmission signal 903_1, and outputs multiplied signal 905_1.Multiplied signal 905_1 is output from antenna 906_1 as radio waves.

When transmission signal 903_1 is expressed as Tx1(t) (t is time) andthe multiplication coefficient is expressed as W1 (W1 can be defined asa complex number and thus may be a real number), multiplied signal 905_1can be expressed as Tx1(t)×W1.

Multiplier 904_2 receives inputs of transmission signal 903_2 andcontrol signal 900, and based on the multiplication coefficient includedin control signal 900, multiplies a multiplication coefficient withtransmission signal 903_2, and outputs multiplied signal 905_2.

Multiplied signal 905_2 is output from antenna 906_2 as radio waves.

When transmission signal 903_2 is expressed as Tx2(t) and themultiplication coefficient is expressed as W2 (W2 can be defined as acomplex number and thus may be a real number), multiplied signal 905_2can be expressed as Tx2(t)×W2.

Multiplier 904_3 receives inputs of transmission signal 903_3 andcontrol signal 900, and based on the multiplication coefficient includedin control signal 900, multiplies a multiplication coefficient withtransmission signal 903_3, and outputs multiplied signal 905_3.Multiplied signal 905_3 is output from antenna 906_3 as radio waves.

When transmission signal 903_3 is expressed as Tx3(t) and themultiplication coefficient is expressed as W3 (W3 can be defined as acomplex number and thus may be a real number), multiplied signal 905_3can be expressed as Tx3(t)×W3.

Multiplier 904_4 receives inputs of transmission signal 903_4 andcontrol signal 900, and based on the multiplication coefficient includedin control signal 900, multiplies a multiplication coefficient withtransmission signal 903_4, and outputs multiplied signal 905_4.Multiplied signal 905_4 is output from antenna 906_4 as radio waves.

When transmission signal 903_4 is expressed as Tx4(t) and themultiplication coefficient is expressed as W4 (W4 can be defined as acomplex number and thus may be a real number), multiplied signal 905_4can be expressed as Tx4(t)×W4.

Note that “the absolute value of W1, the absolute value of W2, theabsolute value of W3, and the absolute value of W4 are equal” may betrue. Here, this is the equivalent of having performed a phase change(it goes without saying that the absolute value of W1, the absolutevalue of W2, the absolute value of W3, and the absolute value of W4 maybe unequal).

Moreover, in FIG. 9, the antenna unit is exemplified as including fourantennas (and four multipliers), but the number of antennas is notlimited to four; the antenna unit may include two or more antennas.

When the configuration of antenna unit #A (109_A) in FIG. 1 is asillustrated in FIG. 9, transmission signal 901 corresponds totransmission signal 108_A in FIG. 1. When the configuration of antennaunit #B (109_B) in FIG. 1 is as illustrated in FIG. 9, transmissionsignal 901 corresponds to transmission signal 108_B in FIG. 1 andtransmission signal 108_B in FIG. 1. However, antenna unit #A (109_A)and antenna unit #B (109_B) need not have the configurations illustratedin FIG. 9; as previously described, the antenna units need not receivean input of control signal 100. For example, antenna unit #A (109_A),antenna unit #B (109_B) illustrated in FIG. 1 may include one antennaand, alternatively, may include a plurality of antennas.

FIG. 10 illustrates an example of a frame configuration of transmissionsignal 108_A illustrated in FIG. 1. In FIG. 10, time is represented onthe horizontal axis. The difference between FIG. 10 and FIG. 6 is thatthe frame configuration illustrated in FIG. 10 is an example of a frameconfiguration when a single-carrier scheme is used, and symbols arepresent along the time axis. In FIG. 10, symbols from time t1 to t22 areshown.

Preamble 1001 in FIG. 10 corresponds to preamble signal 252 in, forexample, FIG. 2, FIG. 3. Here, for example, the preamble may transmitdata (for control purposes), may be a symbol for signal detection, asymbol for frequency and time synchronization, or a symbol for channelestimation (a symbol for propagation path fluctuation estimation).

Control information symbol 1002 in FIG. 10 is a symbol that correspondsto control information symbol signal 253 in, for example, FIG. 2, FIG.3, and is a symbol including control information for realizingdemodulation and decoding of data symbols by the reception device thatreceived the frame illustrated in FIG. 10.

Pilot symbol 1004 illustrated in FIG. 10 is a symbol corresponding topilot signal 251A (pa(t)) such as in FIG. 2, FIG. 3. Pilot symbol 1004is, for example, a PSK symbol, and is used by the reception device thatreceives the frame for, for example, channel estimation (propagationpath variation estimation), frequency offset estimation, and phasevariation estimation. For example, the transmission device illustratedin FIG. 1 and the reception device that receives the frame illustratedin FIG. 10 may share the pilot symbol transmission method.

1003 in FIG. 10 is a data symbol for transmitting data.

Note that mapped signal 201A (mapped signal 105_1 in FIG. 1) is referredto as “stream #1” and mapped signal 201B (mapped signal 105_2 in FIG. 1)is referred to as “stream #2.”

Data symbol 1003 is a symbol that corresponds to a data symbol includedin baseband signal 208A generated in the signal processing illustratedin FIG. 2, FIG. 3. Accordingly, data symbol 1003 satisfies “a symbolincluding both the symbol “stream #1” and the symbol “stream #2””, “thesymbol “stream #1””, or “the symbol “stream #2””, as determined by theconfiguration of the precoding matrix used by weighting synthesizer 203(in other words, data symbol 1003 corresponds to weighting synthesizedsignal 204A (z1(i))).

Note that, although not illustrated in FIG. 10, the frame may includesymbols other than a preamble, control information symbol, data symbol,and pilot symbol.

For example, in FIG. 10, the transmission device transmits preamble 1001at time t1, transmits control information symbol 1002 at time t2,transmits data symbols 1003 from time t3 to time t11, transmits pilotsymbol 1004 at time t12, transmits data symbols 1003 from time t13 totime t21, and transmits pilot symbol 1004 at time t22.

FIG. 11 illustrates an example of a frame configuration of transmissionsignal 108_B illustrated in FIG. 1. In FIG. 11, time is represented onthe horizontal axis. The difference between FIG. 11 and FIG. 7 is thatthe frame configuration illustrated in FIG. 11 is an example of a frameconfiguration when a single-carrier scheme is used, and symbols arepresent along the time axis. In FIG. 11, symbols from time t1 to t22 areshown.

Preamble 1101 in FIG. 11 corresponds to preamble signal 252 in, forexample, FIG. 2, FIG. 3. Here, a preamble may transmit data (for controlpurposes), and may be configured as, for example, a symbol for signaldetection, a signal for performing frequency and time synchronization,or a symbol for performing channel estimation (a symbol for performingpropagation path fluctuation estimation).

Control information symbol 1102 in FIG. 11 is a symbol that correspondsto control information symbol signal 253 in, for example, FIG. 2, FIG.3, and is a symbol including control information for realizingdemodulation and decoding of data symbols by the reception device thatreceived the frame illustrated in FIG. 11.

Pilot symbol 1104 illustrated in FIG. 11 is a symbol corresponding topilot signal 251B (pb(t)) such as in FIG. 2, FIG. 3. Pilot symbol 1104is, for example, a PSK symbol, and is used by the reception device thatreceives the frame for, for example, channel estimation (propagationpath variation estimation), frequency offset estimation, and phasevariation estimation. For example, the transmission device illustratedin FIG. 1 and the reception device that receives the frame illustratedin FIG. 11 may share the pilot symbol transmission method.

1103 in FIG. 11 is a data symbol for transmitting data.

Note that mapped signal 201A (mapped signal 105_1 in FIG. 1) is referredto as “stream #1” and mapped signal 201B (mapped signal 105_2 in FIG. 1)is referred to as “stream #2.”

Data symbol 1103 is a symbol that corresponds to a data symbol includedin baseband signal 208B generated in the signal processing illustratedin FIG. 2, FIG. 3. Accordingly, data symbol 1103 satisfies “a symbolincluding both the symbol “stream #1” and the symbol “stream #2””, “thesymbol “stream #1””, or “the symbol “stream #2””, as determined by theconfiguration of the precoding matrix used by weighting synthesizer 203(in other words, data symbol 1103 corresponds to phase-changed signal206B (z2(i))).

Note that, although not illustrated in FIG. 11, the frame may includesymbols other than a preamble, control information symbol, data symbol,and pilot symbol.

For example, in FIG. 11, the transmission device transmits preamble 1101at time t1, transmits control information symbol 1102 at time t2,transmits data symbols 1103 from time t3 to time t11, transmits pilotsymbol 1104 at time t12, transmits data symbols 1103 from time t13 totime t21, and transmits pilot symbol 1104 at time t22.

When a symbol is present at time tp in FIG. 10 and a symbol is presentat time tp in FIG. 10 (where p is an integer that is greater than orequal to 1), the symbol at time tp in FIG. 10 and the symbol at time tpin FIG. 11 are transmitted at the same time and same frequency (forexample, the data symbol at time t3 in FIG. 10 and the data symbol attime t3 in FIG. 11 are transmitted at the same time and same frequency).Note that the frame configuration is not limited to the configurationsillustrated in FIG. 10 and FIG. 11; FIG. 10 and FIG. 11 are mereexamples of frame configurations.

Moreover, a method in which the preamble and control information symbolin FIG. 10 and FIG. 11 transmit the same data (same control information)may be used.

Note that this is under the assumption that the frame of FIG. 10 and theframe of FIG. 11 are received at the same time by the reception device,but even when the frame of FIG. 10 or the frame of FIG. 11 has beenreceived, the reception device can obtain the data transmitted by thetransmission device.

FIG. 12 illustrates an example of a method of arranging symbols on thetime axis for weighting synthesized signal 204A (z1(i)) andphase-changed signal 206B (z2(i)).

In FIG. 12, for example, zp(0) is shown. Here, q is 1 or 2. Accordingly,zp(0) in FIG. 12 indicates “in z1(i) and z2(i), z1(0) and z2(0) whensymbol number i=0.” Similarly, zp(1) indicates “in z1(i) and z2(i),z1(1) and z2(1) when symbol number i=1” (in other words, zp(X) indicates“in z1(i) and z2(i), z1(X) and z2(X) when symbol number i=X”). Note thatthis also applies to FIG. 13, FIG. 14, and FIG. 15.

As illustrated in FIG. 12, symbol zp(0) whose symbol number i=0 isarranged at time 0, symbol zp(1) whose symbol number i=1 is arranged attime 1, symbol zp(2) whose symbol number i=2 is arranged at time 2,symbol zp(3) whose symbol number i=3 is arranged at time 3, and othersymbols are arranged in a similar fashion. With this, symbols arearranged on the time axis for weighting synthesized signal 204A (z1(i))and phase-changed signal 206B (z2(i)). However, FIG. 12 merelyillustrates one example; the relationship between time and symbol numberis not limited to this example.

FIG. 13 illustrates an example of a method of arranging symbols on thefrequency axis for weighting synthesized signal 204A (z1(i)) andphase-changed signal 206B (z2(i)).

As illustrated in FIG. 13, symbol zp(0) whose symbol number i=0 isarranged at carrier 0, symbol zp(1) whose symbol number i=1 is arrangedat carrier 1, symbol zp(2) whose symbol number i=2 is arranged atcarrier 2, symbol zp(3) whose symbol number i=3 is arranged at carrier3, and other symbols are arranged in a similar fashion. With this,symbols are arranged on the frequency axis for weighting synthesizedsignal 204A (z1(i)) and phase-changed signal 206B (z2(i)). However, FIG.13 merely illustrates one example; the relationship between frequencyand symbol number is not limited to this example.

FIG. 14 illustrates an example of an arrangement of symbols on the timeand frequency axes for weighting synthesized signal 204A (z1(i)) andphase-changed signal 206B (z2(i)).

As illustrated in FIG. 14, symbol zp(0) whose symbol number i=0 isarranged at time 0 and carrier 0, symbol zp(1) whose symbol number i=1is arranged at time 0 and carrier 1, symbol zp(2) whose symbol numberi=2 is arranged at time 1 and carrier 0, symbol zp(3) whose symbolnumber i=3 is arranged at time 1 and carrier 1, and other symbols arearranged in a similar fashion. With this, symbols are arranged on thetime and frequency axes for weighting synthesized signal 204A (z1(i))and phase-changed signal 206B (z2(i)). However, FIG. 14 merelyillustrates one example; the relationship between time and frequency andsymbol number is not limited to this example.

FIG. 15 illustrates an example of an arrangement of symbols relative totime for weighting synthesized signal 204A (z1(i)) and phase-changedsignal 206B (z2(i)). Note FIG. 15 illustrates an example of anarrangement of symbols when an interleaver (component for rearrangingsymbols) is included in radio units 107_A, 107_B illustrated in FIG. 1(note that the configuration of radio units 107_A, 107_B illustrated inFIG. 1 when including an interleaver (component for rearranging symbols)will be described later with reference to FIG. 18).

As illustrated in FIG. 15, symbol zp(0) whose symbol number i=0 isarranged at time 0, symbol zp(1) whose symbol number i=1 is arranged attime 16, symbol zp(2) whose symbol number i=2 is arranged at time 12,symbol zp(3) whose symbol number i=3 is arranged at time 5, and othersymbols are arranged in a similar fashion. With this, symbols arearranged on the time axis for weighting synthesized signal 204A (z1(i))and phase-changed signal 206B (z2(i)). However, FIG. 15 merelyillustrates one example; the relationship between time and symbol numberis not limited to this example.

FIG. 16 illustrates an example of an arrangement of symbols relative totime for weighting synthesized signal 204A (z1(i)) and phase-changedsignal 206B (z2(i)). Note FIG. 16 illustrates an example of anarrangement of symbols when an interleaver (component for rearrangingsymbols) is included in radio units 107_A, 107_B illustrated in FIG. 1(note that the configuration of radio units 107_A, 107_B illustrated inFIG. 1 when including an interleaver (component for rearranging symbols)will be described later with reference to FIG. 18).

As illustrated in FIG. 16, symbol zp(0) whose symbol number i=0 isarranged at carrier 0, symbol zp(1) whose symbol number i=1 is arrangedat carrier 16, symbol zp(2) whose symbol number i=2 is arranged atcarrier 12, symbol zp(3) whose symbol number i=3 is arranged at carrier5, and other symbols are arranged in a similar fashion. With this,symbols are arranged on the time axis for weighting synthesized signal204A (z1(i)) and phase-changed signal 206B (z2(i)). However, FIG. 16merely illustrates one example; the relationship between frequency andsymbol number is not limited to this example.

FIG. 17 illustrates an example of an arrangement of symbols relative totime for weighting synthesized signal 204A (z1(i)) and phase-changedsignal 206B (z2(i)). Note FIG. 17 illustrates an example of anarrangement of symbols when an interleaver (component for rearrangingsymbols) is included in radio units 107_A, 107_B illustrated in FIG. 1(note that the configuration of radio units 107_A, 107_B illustrated inFIG. 1 when including an interleaver (component for rearranging symbols)will be described later with reference to FIG. 18).

As illustrated in FIG. 17, symbol zp(0) whose symbol number i=0 isarranged at time 1 and carrier 1, symbol zp(1) whose symbol number i=1is arranged at time 3 and carrier 3, symbol zp(2) whose symbol numberi=2 is arranged at time 1 and carrier 0, symbol zp(3) whose symbolnumber i=3 is arranged at time 1 and carrier 3, and other symbols arearranged in a similar fashion. With this, symbols are arranged on thetime and frequency axes for weighting synthesized signal 204A (z1(i))and phase-changed signal 206B (z2(i)). However, FIG. 17 merelyillustrates one example; the relationship between time and frequency andsymbol number is not limited to this example.

FIG. 18 illustrates an example of arrangement of symbols when radiounits 107_A, 107_B illustrated in FIG. 1 include an interleaver(component for rearranging symbols).

Interleaver (rearranger) 1802 receives inputs of signal-processed signal1801 (corresponding to 105_1, 105_2 in FIG. 1) and control signal 1800(corresponding to 100 in FIG. 1), and, for example, in accordance withcontrol signal 1800, rearrange the symbols, and output rearranged signal1803. Note that an example of the rearrangement of symbols is asdescribed with reference to FIG. 14 through FIG. 17.

Signal processor 1804 receives inputs of rearranged signal 1803 andcontrol signal 1800, and in accordance with control signal 1800,performs signal processing, and outputs signal-processed signal 1805.For example, when the transmission device illustrated in FIG. 1 supportsboth a single-carrier scheme and an OFDM scheme, based on control signal1800, signal processor 1804 either performs signal processing inaccordance with the single-carrier scheme or performs signal processingin accordance with the OFDM scheme.

RF unit 1806 receives inputs of signal-processed signal 1805 and controlsignal 1800, and based on control signal 1800, performs processing suchas frequency conversion, and outputs modulated signal 1807.

Transmission power amplifier 1808 receives an input of modulated signal1807, performs signal amplification, and outputs modulated signal 1809.

FIG. 19 illustrates one example of a configuration of a reception devicethat receives a modulated signal upon the transmission deviceillustrated in FIG. 1 transmitting, for example, the frame configurationillustrated in FIG. 6 or FIG. 7, or a transmission signal illustrated inFIG. 10 or FIG. 11.

Radio unit 1903X receives an input of reception signal 1902X received byantenna unit #X (1901X), applies processing such as frequency conversionand a Fourier transform, and outputs baseband signal 1904X.

Similarly, radio unit 1903Y receives an input of reception signal 1902Yreceived by antenna unit #Y (1901Y), applies processing such asfrequency conversion and a Fourier transform, and outputs basebandsignal 1904Y.

Note FIG. 19 illustrates a configuration in which antenna unit #X(1901X) and antenna unit #Y (1901Y) receive control signal 1910 as aninput, but antenna unit #X (1901X) and antenna unit #Y (1901Y) may beconfigured to not receive an input of control signal 1910. Operationsperformed when control signal 1910 is present as an input will bedescribed in detail later.

FIG. 20 illustrates the relationship between the transmission device andthe reception device. Antennas 2001_1 and 2001_2 in FIG. 20 aretransmitting antennas, and antenna 2001_1 in FIG. 20 corresponds toantenna unit #A (109_A) in FIG. 1. Antenna 2001_2 in FIG. 20 correspondsto antenna unit #B (109_B) in FIG. 1.

Antennas 2002_1 and 2002_2 in FIG. 20 are receiving antennas, andantenna 2002_1 in FIG. 20 corresponds to antenna unit #X (1901X) in FIG.19. Antenna 2002_2 in FIG. 20 corresponds to antenna unit #Y (1901Y) inFIG. 19.

As illustrated in FIG. 20, the signal transmitted from transmittingantenna 2001_1 is u1(i), the signal transmitted from transmittingantenna 2001_2 is u2(i), the signal received by receiving antenna 2002_1is r1(i), and the signal received by receiving antenna 2002_2 is r2(i)Note that i is a symbol number, and, for example, is an integer that isgreater than or equal to 0.

The propagation coefficient from transmitting antenna 2001_1 toreceiving antenna 2002_1 is h11(i), the propagation coefficient fromtransmitting antenna 2001_1 to receiving antenna 2002_2 is h21(i), thepropagation coefficient from transmitting antenna 2001_2 to receivingantenna 2002_1 is h12(i), and the propagation coefficient fromtransmitting antenna 2001_2 to receiving antenna 2002_2 is h22(i). Inthis case, the following relation equation holds true.

$\begin{matrix}{\left\lbrack {{MATH}.\mspace{14mu} 46} \right\rbrack\mspace{490mu}} & \; \\{\begin{pmatrix}{r\; 1(i)} \\{r\; 2(i)}\end{pmatrix} = {{\begin{pmatrix}{h\; 11(i)} & {h\; 12(i)} \\{h\; 21(i)} & {h\; 22(i)}\end{pmatrix}\begin{pmatrix}{u\; 1(i)} \\{u\; 2(i)}\end{pmatrix}} + \begin{pmatrix}{n\; 1(i)} \\{n\; 2(i)}\end{pmatrix}}} & {{Equation}\mspace{14mu}(46)}\end{matrix}$

Note that n1(i) and n2(i) are noise.

Channel estimation unit 1905_1 of modulated signal u1 in FIG. 19receives an input of baseband signal 1904X, and using the preambleand/or pilot symbol illustrated in FIG. 6 or FIG. 7 (or FIG. 10 or FIG.11), performs channel estimation on modulated signal u1, that is to say,estimates h11(i) in Equation (46), and outputs channel estimated signal1906_1.

Channel estimation unit 1905_2 of modulated signal u2 receives an inputof baseband signal 1904X, and using the preamble and/or pilot symbolillustrated in FIG. 6 or FIG. 7 (or FIG. 10 or FIG. 11), performschannel estimation on modulated signal u2, that is to say, estimatesh12(i) in Equation (46), and outputs channel estimated signal 1906_2.

Channel estimation unit 1907_1 of modulated signal u1 receives an inputof baseband signal 1904Y, and using the preamble and/or pilot symbolillustrated in FIG. 6 or FIG. 7 (or FIG. 10 or FIG. 11), performschannel estimation on modulated signal u1, that is to say, estimatesh21(i) in Equation (46), and outputs channel estimated signal 1908_1.

Channel estimation unit 1907_2 of modulated signal u2 receives an inputof baseband signal 1904Y, and using the preamble and/or pilot symbolillustrated in FIG. 6 or FIG. 7 (or FIG. 10 or FIG. 11), performschannel estimation on modulated signal u2, that is to say, estimatesh22(i) in Equation (46), and outputs channel estimated signal 1908_2.

Control information decoder 1909 receives inputs of baseband signals1904X and 1904Y, demodulates and decodes control information including“other symbols” in FIG. 6 and FIG. 7 (or FIG. 10 and FIG. 11), andoutputs control signal 1910 including control information.

Signal processor 1911 receives inputs of channel estimated signals1906_1, 1906_2, 1908_1, 1908_2, baseband signals 1904X, 1904Y, andcontrol signal 1910, and performs demodulation and decoding using therelationship in Equation (46) or based on control information in controlsignal 1910 (for example, information on a modulation scheme or a schemerelating to the error correction code), and outputs reception data 1912.

Note that control signal 1910 need not be generated via the methodillustrated in FIG. 19. For example, control signal 1910 in FIG. 19 maybe generated based on information transmitted by a device that is thecommunication partner (FIG. 1) in FIG. 8, and, alternatively, the devicein FIG. 19 may include an input unit, and control signal 1910 may begenerated based on information input from the input unit.

FIG. 21 illustrates one example of a configuration of antenna unit #X(1901X) and antenna unit #Y (1901Y) illustrated in FIG. 19 (antenna unit#X (1901X) and antenna unit #Y (1901Y) are exemplified as including aplurality of antennas).

Multiplier 2103_1 receives inputs of reception signal 2102_1 received byantenna 2101_1 and control signal 2100, and based on information on amultiplication coefficient included in control signal 2100, multipliesreception signal 2102_1 with the multiplication coefficient, and outputsmultiplied signal 2104_1.

When reception signal 2102_1 is expressed as Rx1(t) (t is time) and themultiplication coefficient is expressed as D1 (D1 can be defined as acomplex number and thus may be a real number), multiplied signal 2104_1can be expressed as Rx1(t)×D1.

Multiplier 2103_2 receives inputs of reception signal 2102_2 received byantenna 2101_2 and control signal 2100, and based on information on amultiplication coefficient included in control signal 2100, multipliesreception signal 2102_2 with the multiplication coefficient, and outputsmultiplied signal 2104_2.

When reception signal 2102_2 is expressed as Rx2(t) and themultiplication coefficient is expressed as D2 (D2 can be defined as acomplex number and thus may be a real number), multiplied signal 2104_2can be expressed as Rx2(t)×D2.

Multiplier 2103_3 receives inputs of reception signal 2102_3 received byantenna 2101_3 and control signal 2100, and based on information on amultiplication coefficient included in control signal 2100, multipliesreception signal 2102_3 with the multiplication coefficient, and outputsmultiplied signal 2104_3.

When reception signal 2102_3 is expressed as Rx3(t) and themultiplication coefficient is expressed as D3 (D3 can be defined as acomplex number and thus may be a real number), multiplied signal 2104_3can be expressed as Rx3(t)×D3.

Multiplier 2103_4 receives inputs of reception signal 2102_4 received byantenna 2101_4 and control signal 2100, and based on information on amultiplication coefficient included in control signal 2100, multipliesreception signal 2102_4 with the multiplication coefficient, and outputsmultiplied signal 2104_4.

When reception signal 2102_4 is expressed as Rx4(t) and themultiplication coefficient is expressed as D4 (D4 can be defined as acomplex number and thus may be a real number), multiplied signal 2104_4can be expressed as Rx4(t)×D4.

Synthesizer 2105 receives inputs of multiplied signals 2104_1, 2104_2,2104_3, and 1004_4, synthesizes multiplied signals 2104_1, 2104_2,2104_3, and 2104_4, and outputs synthesized signal 2106. Note thatsynthesized signal 2106 is expressed asRx1(t)×D1+Rx2(t)×D2+Rx3(t)×D3+Rx4(t)×D4.

In FIG. 21, the antenna unit is exemplified as including four antennas(and four multipliers), but the number of antennas is not limited tofour; the antenna unit may include two or more antennas.

When antenna unit #X (1901X) illustrated in FIG. 19 has theconfiguration illustrated in FIG. 21, reception signal 1902X correspondsto synthesized signal 2106 in FIG. 21, and control signal 1910corresponds to control signal 2100 in FIG. 10. When antenna unit #Y(1901Y) illustrated in FIG. 19 has the configuration illustrated in FIG.21, reception signal 1902Y corresponds to synthesized signal 2106 inFIG. 21, and control signal 1910 corresponds to control signal 2100 inFIG. 21.

However, antenna unit #X (1901X) and antenna unit #Y (1901Y) need nothave the configurations illustrated in FIG. 21; as previously described,the antenna units need not receive an input of control signal 1910.antenna unit #X (1901X) and antenna unit #Y (1901Y) may each becomprised on a single antenna.

Note that control signal 1900 may be generated based on informationtransmitted by a device that is the communication partner, and,alternatively, the device may include an input unit, and control signal1900 may be generated based on information input from the input unit.

With the transmission method described in this embodiment, by thetransmission device illustrated in FIG. 1 transmitting the modulatedsignal, the reception device in FIG. 19 that receives the modulatedsignal transmitted by the transmission device in FIG. 1 can reduce theinfluence of phase noise and the influence of non-linear distortion, andthus can achieve an advantageous effect that the data reception qualityis improved.

Note that the modulated signal transmitted by the transmission deviceillustrated in FIG. 1 may be a single-carrier scheme modulated signaland, alternatively, may be a multi-carrier scheme modulated signal suchas an OFDM modulated signal. Moreover, the modulated signal may beapplied with a spread spectrum communication method.

Control signal 100 in the transmission device illustrated in FIG. 1 mayinclude control information for specifying transmission using asingle-carrier scheme or transmission using a multi-carrier scheme suchas OFDM. When control signal 100 indicates transmission using asingle-carrier scheme, the transmission device illustrated in FIG. 1transmits a single-carrier scheme modulated signal, and when controlsignal 100 indicates transmission using a multi-carrier scheme such asOFDM, the transmission device illustrated in FIG. 1 transmits amulti-carrier scheme modulated signal such as an OFDM modulated signal.Note that as a result of the transmission signal illustrated in FIG. 1transmitting, to the reception device illustrated in FIG. 19, controlinformation for specifying transmission using a single-carrier scheme ortransmission using a multi-carrier scheme such as OFDM, the receptiondevice illustrated in FIG. 19 can receive, demodulate, and decode themodulated signal transmitted in FIG. 1.

Embodiment 2

In this embodiment, differences from Embodiment 1 will be described whenthe transmission device illustrated in FIG. 1 can transmit both asingle-carrier scheme modulated signal and a multi-carrier schememodulated signal such as an OFDM modulated signal, or one or the other.

In this embodiment, the following three types of transmission deviceswill be considered.

First Transmission Device:

The first transmission device is a transmission device capable ofselectively transmitting both a single-carrier scheme modulated signaland a multi-carrier scheme modulated signal such as an OFDM modulatedsignal. Control signal 100 in the transmission device illustrated inFIG. 1 includes control information for specifying transmission using asingle-carrier scheme or transmission using a multi-carrier scheme suchas OFDM, and when control signal 100 indicates transmission using asingle-carrier scheme, the transmission device illustrated in FIG. 1transmits a single-carrier scheme modulated signal, and when controlsignal 100 indicates transmission using a multi-carrier scheme such asOFDM, the transmission device illustrated in FIG. 1 transmits amulti-carrier scheme modulated signal such as an OFDM modulated signal.Note that as a result of the transmission device illustrated in FIG. 1transmitting, to the reception device illustrated in FIG. 19, controlinformation for specifying transmission using a single-carrier scheme ortransmission using a multi-carrier scheme such as OFDM, the receptiondevice illustrated in FIG. 19 can receive, demodulate, and decode themodulated signal transmitted by the transmission device illustrated inFIG. 1.

Second Transmission Device:

The second transmission device is a transmission device capable oftransmitting a single-carrier scheme modulated signal. When controlsignal 100 in the transmission device illustrated in FIG. 1 includescontrol information for specifying transmission using a single-carrierscheme or transmission using a multi-carrier scheme such as OFDM, thesecond transmission device can only select transmission using asingle-carrier scheme as this control information. Accordingly, thetransmission device illustrated in FIG. 1 transmits a single-carrierscheme modulated signal. Note that as a result of the transmissiondevice illustrated in FIG. 1 transmitting, to the reception deviceillustrated in FIG. 19, control information for specifying transmissionusing a single-carrier scheme or transmission using a multi-carrierscheme such as OFDM, the reception device illustrated in FIG. 19 canreceive, demodulate, and decode the modulated signal transmitted by thetransmission device illustrated in FIG. 1.

Third Transmission Device:

The third transmission device is a transmission device capable oftransmitting a multi-carrier scheme modulated signal such as an OFDMmodulated signal. When control signal 100 in the transmission deviceillustrated in FIG. 1 includes control information for specifyingtransmission using a single-carrier scheme or transmission using amulti-carrier scheme such as OFDM, the second transmission device canonly select transmission using a multi-carrier scheme such as OFMD asthis control information. Accordingly, the transmission deviceillustrated in FIG. 1 transmits a multi-carrier scheme modulated signalsuch as a OFDM modulated signal. Note that as a result of thetransmission device illustrated in FIG. 1 transmitting, to the receptiondevice illustrated in FIG. 19, control information for specifyingtransmission using a single-carrier scheme or transmission using amulti-carrier scheme such as OFDM, the reception device illustrated inFIG. 19 can receive, demodulate, and decode the modulated signaltransmitted by the transmission device illustrated in FIG. 1.

In Embodiment 1, the configuration of the transmission device, theconfiguration of the reception device that receives the modulated signaltransmitted by the transmission device, the frame configuration examplein the case of single-carrier scheme, and the frame configurationexample in the case of multi-carrier scheme such as OFDM have alreadybeen described, so repeated description will be omitted.

In this embodiment, as a transmission signal method for a modulatedsignal when a single-carrier scheme is used, any one of the firstselection method, second selection method, or third selection methoddescribed in Embodiment 1 is applied, and the transmission deviceillustrated in FIG. 1 transmits the modulated signal. Here, in thesecond transmission device, influence of phase noise in the RF unit andinfluence of non-linear distortion in the transmission power amplifiercan be reduced, and depending on the transmission method, it is possibleto achieve an advantageous effect of transmit diversity. Accordingly, inthe reception device that receives the modulated signal transmitted bythe second transmission device, it is possible to achieve anadvantageous effect of improvement in data reception quality.

In this embodiment, the following methods for transmitting amulti-carrier scheme modulated signal such as an OFDM modulated signalwill be considered.

Fourth Selection Method:

The transmission device illustrated in FIG. 1 switches the transmissionmethod of the modulated signal based on information on the transmissionmethod included in control signal 100. Here, the transmission deviceillustrated in FIG. 1 can select the following transmission methods.

Transmission Method #4-1:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is BPSK (or π/2 shift BPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #4-2:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is QPSK (or π/2 shift QPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #4-3:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or a modulation scheme inwhich 16 signal points are in the in-phase I-quadrature Q plane, such as16APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #4-4:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or a modulation scheme inwhich 64 signal points are in the in-phase I-quadrature Q plane, such as64APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #4-5:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is BPSK (or π/2 shift BPSK), and themodulation scheme of s2(i) is BPSK (or π/2 shift BPSK). Here, twomodulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Transmission Method #4-6:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is QPSK (or π/2 shift QPSK). Here, twomodulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Transmission Method #4-7:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)).

Here, θ≠0 radians in Equation (13) through Equation (20) (note that θ isgreater than or equal to 0 radians and less than 2π radians (0radians≤θ<2π radians)) (when θ=π/4 radians (45 degrees), the averagetransmission power of the modulated signals transmitted from theantennas is equal).

Transmission Method #4-8:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Transmission Method #4-9:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 64APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Alternatively, two streams are transmitted (s1(i) and s2(i) aretransmitted). The modulation scheme of s1(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 16APSK (a shift may beperformed)), and the modulation scheme of s2(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)). Here, two modulated signals are transmitted. The firstmodulated signal is transmitted using one or more antennas, and thesecond modulated signal is transmitted using one or more antennas. Here,based on FIG. 2 and FIG. 3, precoding (weighted synthesis) is performedusing any one of the (precoding) matrices in Equation (13) throughEquation (20), and thereafter, a phase change is performed (by phasechanger 205B), and the two streams are transmitted (note that a phasechange need not be performed, coefficient multiplication is alsoperformed (by coefficient multipliers 301A, 302A)). Here, θ=0 radians inEquation (13) through Equation (20) (note that θ is greater than orequal to 0 radians and less than a radians (0 radians≤θ<2π radians)).

Alternatively, two streams are transmitted (s1(i) and s2(i) aretransmitted). The modulation scheme of s1(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)), and the modulation scheme of s2(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)). Here, two modulated signals are transmitted. The firstmodulated signal is transmitted using one or more antennas, and thesecond modulated signal is transmitted using one or more antennas. Here,based on FIG. 2 and FIG. 3, precoding (weighted synthesis) is performedusing any one of the (precoding) matrices in Equation (13) throughEquation (20), and thereafter, a phase change is performed (by phasechanger 205B), and the two streams are transmitted (note that a phasechange need not be performed, coefficient multiplication is alsoperformed (by coefficient multipliers 301A, 302A)).

Next, precoding processing will be described.

In the transmission device illustrated in FIG. 1, a plurality ofprecoding matrices expressed by any of Equation (13) through Equation(20) are provided for performing precoding processing. For example, N (Nis an integer that is greater than or equal to 2) precoding matrices areprepared. Here, the N precoding matrices are referred to as i-th matrix(i is an integer that is greater than or equal to 1 and less than orequal to N) (the i-th matrix may be expressed as any one of the matrixesin Equation (13) through Equation (20)).

Based on control signal 200, weighting synthesizer 203 illustrated inFIG. 2, FIG. 3 uses one matrix specified by control signal 200 fromamong the N matrices from the first matrix to the N-th matrix, andperforms precoding.

Note that the N matrices include at least one precoding matrix thatsatisfies any one of Equation (13) through Equation (20) in which θ=0,and include at least one precoding matrix that satisfies any one ofEquation (13) through Equation (20) in which θ≠0.

Note that in the fourth selection method, the transmission method neednot correspond to all transmission methods from transmission method #4-1through transmission method #4-9. For example, in the fourth selectionmethod, the transmission method may correspond to one or moretransmission method from among the following three transmission methods:transmission method #4-5, transmission method #4-6, and transmissionmethod #4-7. In the fourth transmission method, the transmission methodmay correspond to one or more transmission method from among thefollowing two transmission methods: transmission method #4-8 andtransmission method #4-9.

In the fourth selection method, the transmission method need notcorrespond to transmission method #4-1 (in the fourth selection method,the transmission method need not include transmission method #4-1 in thetransmission method selection candidates in the transmission deviceillustrated in FIG. 1). The fourth selection method may include atransmission method other than those from transmission method #4-1 totransmission method #4-9.

Here, the following is satisfied.

Transmission Method #4-1:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 2.

Transmission Method #4-2:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 4.

Transmission Method #4-3:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 16.

Transmission Method #4-4:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 64.

Transmission Method #4-5:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 2 and less than or equal to 4. Theadvantageous effect of transmit diversity is achievable.

Transmission Method #4-6:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 4 and less than or equal to 16. Theadvantageous effect of transmit diversity is achievable.

Transmission Method #4-7:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 4 and less than or equal to 64. Theadvantageous effect of transmit diversity is achievable.

Transmission Method #4-8:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 16 and less than or equal to 256.The advantageous effect of transmit diversity is achievable.

Transmission Method #4-9:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 64 and less than orequal to 4096. The advantageous effect of transmit diversity may beachievable.

As described above, the selection method for the transmission methodwhen a single-carrier scheme modulated signal is transmitted and theselection method for the transmission method when a multi-carrier schememodulated signal such as an OFDM modulated signal is transmitted aredifferent.

The reason for why the fourth selection method is used as the selectionmethod for the transmission method when a multi-carrier scheme modulatedsignal such as an OFDM modulated signal is transmitted will bedescribed.

As a transmission device that transmits a multi-carrier scheme modulatedsignal such as an OFDM modulated signal, regardless of the modulationscheme used, it is necessary to satisfy the conditions that theinfluence of phase noise in the RF unit is small and the influence ofnon-linear distortion in the transmission power amplifier is small (whenthese conditions are not satisfied, in the reception device thatreceives the modulated signal transmitted by the transmission device, itis difficult to achieve high data reception quality (since thetransmission device transmits modulated signals for a plurality ofcarriers at the same time, regardless of the modulation scheme used, thePAPR is large, so the above-described conditions are important)).Accordingly, when the transmission device illustrated in FIG. 1 is thethird transmission device (or the first transmission device), by usingthe fourth selection method, when a plurality of modulated signals aretransmitted, it is possible to increase the probability that high datareception quality can be achieved by the reception device, so performingprecoding is given as much priority as possible.

As described above, regardless of whether the transmission devicetransmits a single-carrier scheme modulated signal or a multi-carrierscheme modulated signal such as an OFDM modulated signal, the receptiondevice that receives the modulated signal transmitted by thetransmission device can achieve an advantageous effect that it ispossible to achieve an even higher data reception quality.

Next, a fifth selection method different than the fourth selectionmethod that is used when transmitting a multi-carrier scheme modulatedsignal such as an OFDM modulated signal will be described.

Fifth Selection Method: Transmission Method #5-1:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is BPSK (or π/2 shift BPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #5-2:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is QPSK (or π/2 shift QPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #5-3:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or a modulation scheme inwhich 16 signal points are in the in-phase I-quadrature Q plane, such as16APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #5-4:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or a modulation scheme inwhich 64 signal points are in the in-phase I-quadrature Q plane, such as64APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #5-5:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is BPSK (or π/2 shift BPSK), and themodulation scheme of s2(i) is BPSK (or π/2 shift BPSK). Here, twomodulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Transmission Method #5-6:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is QPSK (or π/2 shift QPSK). Here, twomodulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Transmission Method #5-7:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)) (when 0=π/4 radians (45degrees), the average transmission power of the modulated signalstransmitted from the antennas is equal).

Transmission Method #5-8:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)).

Next, precoding processing will be described.

In the transmission device illustrated in FIG. 1, a plurality ofprecoding matrices expressed by any of Equation (13) through Equation(20) are provided for performing precoding processing. For example, N (Nis an integer that is greater than or equal to 2) precoding matrices areprepared. Here, the N precoding matrices are referred to as i-th matrix(i is an integer that is greater than or equal to 1 and less than orequal to N) (the i-th matrix may be expressed as any one of the matrixesin Equation (13) through Equation (20)).

Based on control signal 200, weighting synthesizer 203 illustrated inFIG. 2, FIG. 3 uses one matrix specified by control signal 200 fromamong the N matrices from the first matrix to the N-th matrix, andperforms precoding.

Note that the N matrices include at least one precoding matrix thatsatisfies any one of Equation (13) through Equation (20) in which θ=0,and include at least one precoding matrix that satisfies any one ofEquation (13) through Equation (20) in which θ≠0.

Transmission Method #5-9:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 64APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Alternatively, two streams are transmitted (s1(i) and s2(i) aretransmitted). The modulation scheme of s1(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 16APSK (a shift may beperformed)), and the modulation scheme of s2(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)). Here, two modulated signals are transmitted. The firstmodulated signal is transmitted using one or more antennas, and thesecond modulated signal is transmitted using one or more antennas. Here,based on FIG. 2 and FIG. 3, precoding (weighted synthesis) is performedusing any one of the (precoding) matrices in Equation (13) throughEquation (20), and thereafter, a phase change is performed (by phasechanger 205B), and the two streams are transmitted (note that a phasechange need not be performed, coefficient multiplication is alsoperformed (by coefficient multipliers 301A, 302A)). Here, θ=0 radians inEquation (13) through Equation (20) (note that θ is greater than orequal to 0 radians and less than a radians (0 radians≤θ<2π radians)).

Alternatively, two streams are transmitted (s1(i) and s2(i) aretransmitted). The modulation scheme of s1(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)), and the modulation scheme of s2(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)). Here, two modulated signals are transmitted. The firstmodulated signal is transmitted using one or more antennas, and thesecond modulated signal is transmitted using one or more antennas. Here,based on FIG. 2 and FIG. 3, precoding (weighted synthesis) is performedusing any one of the (precoding) matrices in Equation (13) throughEquation (20), and thereafter, a phase change is performed (by phasechanger 205B), and the two streams are transmitted (note that a phasechange need not be performed, coefficient multiplication is alsoperformed (by coefficient multipliers 301A, 302A)).

Next, precoding processing will be described.

In the transmission device illustrated in FIG. 1, a plurality ofprecoding matrices expressed by any of Equation (13) through Equation(20) are provided for performing precoding processing. For example, N (Nis an integer that is greater than or equal to 2) precoding matrices areprepared. Here, the N precoding matrices are referred to as i-th matrix(i is an integer that is greater than or equal to 1 and less than orequal to N) (the i-th matrix may be expressed as any one of the matrixesin Equation (13) through Equation (20)).

Based on control signal 200, weighting synthesizer 203 illustrated inFIG. 2, FIG. 3 uses one matrix specified by control signal 200 fromamong the N matrices from the first matrix to the N-th matrix, andperforms precoding.

Note that the N matrices include at least one precoding matrix thatsatisfies any one of Equation (13) through Equation (20) in which θ=0,and include at least one precoding matrix that satisfies any one ofEquation (13) through Equation (20) in which θ≠0.

Note that in the fifth selection method, the transmission method neednot correspond to all transmission methods from transmission method #5-1through transmission method #5-9. For example, in the fifth selectionmethod, the transmission method may correspond to one or moretransmission method from among the following three transmission methods:transmission method #5-5, transmission method #5-6, and transmissionmethod #5-7. In the fifth transmission method, the transmission methodmay correspond to one or more transmission method from among thefollowing two transmission methods: transmission method #5-8 andtransmission method #5-9.

In the fifth selection method, the transmission method need notcorrespond to transmission method #4-1 (in the fifth selection method,the transmission method need not include transmission method #5-1 in thetransmission method selection candidates in the transmission deviceillustrated in FIG. 1).

The fifth selection method may include a transmission method other thanthose from transmission method #5-1 to transmission method #5-9.

Here, the following is satisfied.

Transmission Method #5-1:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 2.

Transmission Method #5-2:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 4.

Transmission Method #5-3:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 16.

Transmission Method #5-4:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 64.

Transmission Method #5-5:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 2 and less than or equal to 4. Theadvantageous effect of transmit diversity is achievable.

Transmission Method #5-6:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 4 and less than or equal to 16. Theadvantageous effect of transmit diversity is achievable.

Transmission Method #5-7:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 4 and less than or equal to 64. Theadvantageous effect of transmit diversity is achievable.

Transmission Method #5-8:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 16 and less than orequal to 256. The advantageous effect of transmit diversity may beachievable.

Transmission Method #5-9:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 64 and less than orequal to 4096. The advantageous effect of transmit diversity may beachievable.

As described above, the selection method for the transmission methodwhen a single-carrier scheme modulated signal is transmitted and theselection method for the transmission method when a multi-carrier schememodulated signal such as an OFDM modulated signal is transmitted aredifferent.

The reason for why the fifth selection method is used as the selectionmethod for the transmission method when a multi-carrier scheme modulatedsignal such as an OFDM modulated signal is transmitted will bedescribed.

As a transmission device that transmits a multi-carrier scheme modulatedsignal such as an OFDM modulated signal, regardless of the modulationscheme used, it is necessary to satisfy the conditions that theinfluence of phase noise in the RF unit is small and the influence ofnon-linear distortion in the transmission power amplifier is small (whenthese conditions are not satisfied, in the reception device thatreceives the modulated signal transmitted by the transmission device, itis difficult to achieve high data reception quality (since thetransmission device transmits modulated signals for a plurality ofcarriers at the same time, regardless of the modulation scheme used, thePAPR is large, so the above-described conditions are important)).

Accordingly, when the transmission device illustrated in FIG. 1 is thethird transmission device (or the first transmission device), by usingthe fifth selection method, when a plurality of modulated signals aretransmitted, it is possible to increase the probability that high datareception quality can be achieved by the reception device, so performingprecoding is given as much priority as possible.

As described above, regardless of whether the transmission devicetransmits a single-carrier scheme modulated signal or a multi-carrierscheme modulated signal such as an OFDM modulated signal, the receptiondevice that receives the modulated signal transmitted by thetransmission device can achieve an advantageous effect that it ispossible to achieve an even higher data reception quality.

Next, a sixth selection method different than the fourth selectionmethod and the fifth selection method that is used when transmitting amulti-carrier scheme modulated signal such as an OFDM modulated signalwill be described.

Sixth Selection Method:

Transmission Method #6-1:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is BPSK (or π/2 shift BPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #6-2:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is QPSK (or π/2 shift QPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #6-3:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or a modulation scheme inwhich 16 signal points are in the in-phase I-quadrature Q plane, such as16APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #6-4:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or a modulation scheme inwhich 64 signal points are in the in-phase I-quadrature Q plane, such as64APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #6-5:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is BPSK (or π/2 shift BPSK), and themodulation scheme of s2(i) is BPSK (or π/2 shift BPSK). Here, twomodulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)).

Next, precoding processing will be described.

In the transmission device illustrated in FIG. 1, a plurality ofprecoding matrices expressed by any of Equation (13) through Equation(20) are provided for performing precoding processing. For example, N (Nis an integer that is greater than or equal to 2) precoding matrices areprepared. Here, the N precoding matrices are referred to as i-th matrix(i is an integer that is greater than or equal to 1 and less than orequal to N) (the i-th matrix may be expressed as any one of the matrixesin Equation (13) through Equation (20)).

Based on control signal 200, weighting synthesizer 203 illustrated inFIG. 2, FIG. 3 uses one matrix specified by control signal 200 fromamong the N matrices from the first matrix to the N-th matrix, andperforms precoding.

Note that the N matrices include at least one precoding matrix thatsatisfies any one of Equation (13) through Equation (20) in which θ=0,and include at least one precoding matrix that satisfies any one ofEquation (13) through Equation (20) in which θ≠0.

Transmission Method #6-6:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is QPSK (or π/2 shift QPSK). Here, twomodulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)).

Next, precoding processing will be described.

In the transmission device illustrated in FIG. 1, a plurality ofprecoding matrices expressed by any of Equation (13) through Equation(20) are provided for performing precoding processing. For example, N (Nis an integer that is greater than or equal to 2) precoding matrices areprepared. Here, the N precoding matrices are referred to as i-th matrix(i is an integer that is greater than or equal to 1 and less than orequal to N) (the i-th matrix may be expressed as any one of the matrixesin Equation (13) through Equation (20)).

Based on control signal 200, weighting synthesizer 203 illustrated inFIG. 2, FIG. 3 uses one matrix specified by control signal 200 fromamong the N matrices from the first matrix to the N-th matrix, andperforms precoding.

Note that the N matrices include at least one precoding matrix thatsatisfies any one of Equation (13) through Equation (20) in which θ=0,and include at least one precoding matrix that satisfies any one ofEquation (13) through Equation (20) in which θ≠0.

Transmission Method #6-7:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)) (when 0=π/4 radians (45degrees), the average transmission power of the modulated signalstransmitted from the antennas is equal).

Transmission Method #6-8:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Transmission Method #6-9:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 64APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Alternatively, two streams are transmitted (s1(i) and s2(i) aretransmitted). The modulation scheme of s1(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 16APSK (a shift may beperformed)), and the modulation scheme of s2(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)). Here, two modulated signals are transmitted. The firstmodulated signal is transmitted using one or more antennas, and thesecond modulated signal is transmitted using one or more antennas. Here,based on FIG. 2 and FIG. 3, precoding (weighted synthesis) is performedusing any one of the (precoding) matrices in Equation (13) throughEquation (20), and thereafter, a phase change is performed (by phasechanger 205B), and the two streams are transmitted (note that a phasechange need not be performed, coefficient multiplication is alsoperformed (by coefficient multipliers 301A, 302A)). Here, θ=0 radians inEquation (13) through Equation (20) (note that θ is greater than orequal to 0 radians and less than a radians (0 radians≤θ<2π radians)).

Alternatively, two streams are transmitted (s1(i) and s2(i) aretransmitted). The modulation scheme of s1(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)), and the modulation scheme of s2(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)). Here, two modulated signals are transmitted. The firstmodulated signal is transmitted using one or more antennas, and thesecond modulated signal is transmitted using one or more antennas. Here,based on FIG. 2 and FIG. 3, precoding (weighted synthesis) is performedusing any one of the (precoding) matrices in Equation (13) throughEquation (20), and thereafter, a phase change is performed (by phasechanger 205B), and the two streams are transmitted (note that a phasechange need not be performed, coefficient multiplication is alsoperformed (by coefficient multipliers 301A, 302A)).

Next, precoding processing will be described.

In the transmission device illustrated in FIG. 1, a plurality ofprecoding matrices expressed by any of Equation (13) through Equation(20) are provided for performing precoding processing. For example, N (Nis an integer that is greater than or equal to 2) precoding matrices areprepared. Here, the N precoding matrices are referred to as i-th matrix(i is an integer that is greater than or equal to 1 and less than orequal to N) (the i-th matrix may be expressed as any one of the matrixesin Equation (13) through Equation (20)).

Based on control signal 200, weighting synthesizer 203 illustrated inFIG. 2, FIG. 3 uses one matrix specified by control signal 200 fromamong the N matrices from the first matrix to the N-th matrix, andperforms precoding.

Note that the N matrices include at least one precoding matrix thatsatisfies any one of Equation (13) through Equation (20) in which θ=0,and include at least one precoding matrix that satisfies any one ofEquation (13) through Equation (20) in which θ≠0.

Note that in the sixth selection method, the transmission method neednot correspond to all transmission methods from transmission method #6-1through transmission method #6-9. For example, in the sixth selectionmethod, the transmission method may correspond to one or moretransmission method from among the following three transmission methods:transmission method #6-5, transmission method #6-6, and transmissionmethod #6-7. In the sixth transmission method, the transmission methodmay correspond to one or more transmission method from among thefollowing two transmission methods: transmission method #6-8 andtransmission method #6-9.

In the sixth selection method, the transmission method need notcorrespond to transmission method #6-1 (in the sixth selection method,the transmission method need not include transmission method #6-1 in thetransmission method selection candidates in the transmission deviceillustrated in FIG. 1).

The sixth selection method may include a transmission method other thanthose from transmission method #6-1 to transmission method #6-9.

Here, the following is satisfied.

Transmission Method #6-1:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 2.

Transmission Method #6-2:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 4.

Transmission Method #6-3:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 16.

Transmission Method #6-4:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 64.

Transmission Method #6-5:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 2 and less than or equalto 4. There are cases in which the advantageous effect of transmitdiversity is achievable.

Transmission Method #6-6:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 4 and less than or equalto 16. There are cases in which the advantageous effect of transmitdiversity is achievable.

Transmission Method #6-7:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 4 and less than or equal to 64. Theadvantageous effect of transmit diversity is achievable.

Transmission Method #6-8:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 16 and less than or equal to 256.The advantageous effect of transmit diversity is achievable.

Transmission Method #6-9:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 64 and less than orequal to 4096. The advantageous effect of transmit diversity may beachievable.

As described above, the selection method for the transmission methodwhen a single-carrier scheme modulated signal is transmitted and theselection method for the transmission method when a multi-carrier schememodulated signal such as an OFDM modulated signal is transmitted aredifferent.

The reason for why the sixth selection method is used as the selectionmethod for the transmission method when a multi-carrier scheme modulatedsignal such as an OFDM modulated signal is transmitted will bedescribed.

As a transmission device that transmits a multi-carrier scheme modulatedsignal such as an OFDM modulated signal, regardless of the modulationscheme used, it is necessary to satisfy the conditions that theinfluence of phase noise in the RF unit is small and the influence ofnon-linear distortion in the transmission power amplifier is small (whenthese conditions are not satisfied, in the reception device thatreceives the modulated signal transmitted by the transmission device, itis difficult to achieve high data reception quality (since thetransmission device transmits modulated signals for a plurality ofcarriers at the same time, regardless of the modulation scheme used, thePAPR is large, so the above-described conditions are important)).

Accordingly, when the transmission device illustrated in FIG. 1 is thethird transmission device (or the first transmission device), by usingthe sixth selection method, when a plurality of modulated signals aretransmitted, it is possible to increase the probability that high datareception quality can be achieved by the reception device, so performingprecoding is given as much priority as possible.

As described above, regardless of whether the transmission devicetransmits a single-carrier scheme modulated signal or a multi-carrierscheme modulated signal such as an OFDM modulated signal, the receptiondevice that receives the modulated signal transmitted by thetransmission device can achieve an advantageous effect that it ispossible to achieve an even higher data reception quality.

Next, a seventh selection method different than the fourth selectionmethod, the fifth selection method, and the sixth selection method thatis used when transmitting a multi-carrier scheme modulated signal suchas an OFDM modulated signal will be described.

Seventh Selection Method: Transmission Method #7-1:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is BPSK (or π/2 shift BPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #7-2:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is QPSK (or π/2 shift QPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #7-3:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or a modulation scheme inwhich 16 signal points are in the in-phase I-quadrature Q plane, such as16APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #7-4:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or a modulation scheme inwhich 64 signal points are in the in-phase I-quadrature Q plane, such as64APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #7-5:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is BPSK (or π/2 shift BPSK), and themodulation scheme of s2(i) is BPSK (or π/2 shift BPSK). Here, twomodulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)).

Next, precoding processing will be described.

In the transmission device illustrated in FIG. 1, a plurality ofprecoding matrices expressed by any of Equation (13) through Equation(20) are provided for performing precoding processing. For example, N (Nis an integer that is greater than or equal to 2) precoding matrices areprepared. Here, the N precoding matrices are referred to as i-th matrix(i is an integer that is greater than or equal to 1 and less than orequal to N) (the i-th matrix may be expressed as any one of the matrixesin Equation (13) through Equation (20)).

Based on control signal 200, weighting synthesizer 203 illustrated inFIG. 2, FIG. 3 uses one matrix specified by control signal 200 fromamong the N matrices from the first matrix to the N-th matrix, andperforms precoding.

Note that the N matrices include at least one precoding matrix thatsatisfies any one of Equation (13) through Equation (20) in which θ=0,and include at least one precoding matrix that satisfies any one ofEquation (13) through Equation (20) in which θ≠0.

Transmission Method #7-6:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is QPSK (or π/2 shift QPSK). Here, twomodulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)).

Next, precoding processing will be described.

In the transmission device illustrated in FIG. 1, a plurality ofprecoding matrices expressed by any of Equation (13) through Equation(20) are provided for performing precoding processing. For example, N (Nis an integer that is greater than or equal to 2) precoding matrices areprepared. Here, the N precoding matrices are referred to as i-th matrix(i is an integer that is greater than or equal to 1 and less than orequal to N) (the i-th matrix may be expressed as any one of the matrixesin Equation (13) through Equation (20)).

Based on control signal 200, weighting synthesizer 203 illustrated inFIG. 2, FIG. 3 uses one matrix specified by control signal 200 fromamong the N matrices from the first matrix to the N-th matrix, andperforms precoding.

Note that the N matrices include at least one precoding matrix thatsatisfies any one of Equation (13) through Equation (20) in which θ=0,and include at least one precoding matrix that satisfies any one ofEquation (13) through Equation (20) in which θ≠0.

Transmission Method #7-7:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)) (when 0=π/4 radians (45degrees), the average transmission power of the modulated signalstransmitted from the antennas is equal).

Transmission Method #7-8:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)).

Next, precoding processing will be described.

In the transmission device illustrated in FIG. 1, a plurality ofprecoding matrices expressed by any of Equation (13) through Equation(20) are provided for performing precoding processing. For example, N (Nis an integer that is greater than or equal to 2) precoding matrices areprepared. Here, the N precoding matrices are referred to as i-th matrix(i is an integer that is greater than or equal to 1 and less than orequal to N) (the i-th matrix may be expressed as any one of the matrixesin Equation (13) through Equation (20)).

Based on control signal 200, weighting synthesizer 203 illustrated inFIG. 2, FIG. 3 uses one matrix specified by control signal 200 fromamong the N matrices from the first matrix to the N-th matrix, andperforms precoding.

Note that the N matrices include at least one precoding matrix thatsatisfies any one of Equation (13) through Equation (20) in which θ=0,and include at least one precoding matrix that satisfies any one ofEquation (13) through Equation (20) in which θ≠0.

Transmission Method #7-9:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 64APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Alternatively, two streams are transmitted (s1(i) and s2(i) aretransmitted). The modulation scheme of s1(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 16APSK (a shift may beperformed)), and the modulation scheme of s2(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)). Here, two modulated signals are transmitted. The firstmodulated signal is transmitted using one or more antennas, and thesecond modulated signal is transmitted using one or more antennas. Here,based on FIG. 2 and FIG. 3, precoding (weighted synthesis) is performedusing any one of the (precoding) matrices in Equation (13) throughEquation (20), and thereafter, a phase change is performed (by phasechanger 205B), and the two streams are transmitted (note that a phasechange need not be performed, coefficient multiplication is alsoperformed (by coefficient multipliers 301A, 302A)). Here, θ=0 radians inEquation (13) through Equation (20) (note that θ is greater than orequal to 0 radians and less than a radians (0 radians≤θ<2π radians)).

Alternatively, two streams are transmitted (s1(i) and s2(i) aretransmitted). The modulation scheme of s1(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)), and the modulation scheme of s2(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)). Here, two modulated signals are transmitted. The firstmodulated signal is transmitted using one or more antennas, and thesecond modulated signal is transmitted using one or more antennas. Here,based on FIG. 2 and FIG. 3, precoding (weighted synthesis) is performedusing any one of the (precoding) matrices in Equation (13) throughEquation (20), and thereafter, a phase change is performed (by phasechanger 205B), and the two streams are transmitted (note that a phasechange need not be performed, coefficient multiplication is alsoperformed (by coefficient multipliers 301A, 302A)).

Next, precoding processing will be described.

In the transmission device illustrated in FIG. 1, a plurality ofprecoding matrices expressed by any of Equation (13) through Equation(20) are provided for performing precoding processing. For example, N (Nis an integer that is greater than or equal to 2) precoding matrices areprepared. Here, the N precoding matrices are referred to as i-th matrix(i is an integer that is greater than or equal to 1 and less than orequal to N) (the i-th matrix may be expressed as any one of the matrixesin Equation (13) through Equation (20)).

Based on control signal 200, weighting synthesizer 203 illustrated inFIG. 2, FIG. 3 uses one matrix specified by control signal 200 fromamong the N matrices from the first matrix to the N-th matrix, andperforms precoding.

Note that the N matrices include at least one precoding matrix thatsatisfies any one of Equation (13) through Equation (20) in which θ=0,and include at least one precoding matrix that satisfies any one ofEquation (13) through Equation (20) in which θ≠0.

Note that in the seventh selection method, the transmission method neednot correspond to all transmission methods from transmission method #7-1through transmission method #7-9. For example, in the seventh selectionmethod, the transmission method may correspond to one or moretransmission method from among the following three transmission methods:transmission method #7-5, transmission method #7-6, and transmissionmethod #7-7. In the seventh transmission method, the transmission methodmay correspond to one or more transmission method from among thefollowing two transmission methods: transmission method #7-8 andtransmission method #7-9.

In the seventh selection method, the transmission method need notcorrespond to transmission method #7-1 (in the seventh selection method,the transmission method need not include transmission method #7-1 in thetransmission method selection candidates in the transmission deviceillustrated in FIG. 1). The seventh selection method may include atransmission method other than those from transmission method #7-1 totransmission method #7-9.

Here, the following is satisfied.

Transmission Method #7-1:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 2.

Transmission Method #7-2:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 4.

Transmission Method #7-3:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 16.

Transmission Method #7-4:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 64.

Transmission Method #7-5:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 2 and less than or equalto 4. There are cases in which the advantageous effect of transmitdiversity is achievable.

Transmission Method #7-6:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 4 and less than or equalto 16. There are cases in which the advantageous effect of transmitdiversity is achievable.

Transmission Method #7-7:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 4 and less than or equal to 64. Theadvantageous effect of transmit diversity is achievable.

Transmission Method #7-8:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 16 and less than orequal to 256. The advantageous effect of transmit diversity may beachievable.

Transmission Method #7-9:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 64 and less than orequal to 4096. The advantageous effect of transmit diversity may beachievable.

As described above, the selection method for the transmission methodwhen a single-carrier scheme modulated signal is transmitted and theselection method for the transmission method when a multi-carrier schememodulated signal such as an OFDM modulated signal is transmitted aredifferent.

The reason for why the seventh selection method is used as the selectionmethod for the transmission method when a multi-carrier scheme modulatedsignal such as an OFDM modulated signal is transmitted will bedescribed.

As a transmission device that transmits a multi-carrier scheme modulatedsignal such as an OFDM modulated signal, regardless of the modulationscheme used, it is necessary to satisfy the conditions that theinfluence of phase noise in the RF unit is small and the influence ofnon-linear distortion in the transmission power amplifier is small (whenthese conditions are not satisfied, in the reception device thatreceives the modulated signal transmitted by the transmission device, itis difficult to achieve high data reception quality (since thetransmission device transmits modulated signals for a plurality ofcarriers at the same time, regardless of the modulation scheme used, thePAPR is large, so the above-described conditions are important)).

Accordingly, when the transmission device illustrated in FIG. 1 is thethird transmission device (or the first transmission device), by usingthe seventh selection method, when a plurality of modulated signals aretransmitted, it is possible to increase the probability that high datareception quality can be achieved by the reception device, so performingprecoding is given as much priority as possible.

As described above, regardless of whether the transmission devicetransmits a single-carrier scheme modulated signal or a multi-carrierscheme modulated signal such as an OFDM modulated signal, the receptiondevice that receives the modulated signal transmitted by thetransmission device can achieve an advantageous effect that it ispossible to achieve an even higher data reception quality.

Next, an eighth selection method different than the fourth selectionmethod, the fifth selection method, the sixth selection method, and theseventh selection method that is used when transmitting a multi-carrierscheme modulated signal such as an OFDM modulated signal will bedescribed.

Eighth Selection Method: Transmission Method #8-1:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is BPSK (or π/2 shift BPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #8-2:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is QPSK (or π/2 shift QPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #8-3:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or a modulation scheme inwhich 16 signal points are in the in-phase I-quadrature Q plane, such as16APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #8-4:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or a modulation scheme inwhich 64 signal points are in the in-phase I-quadrature Q plane, such as64APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #8-5:

Either one of transmission method #4-5 or transmission method #6-5.

Transmission Method #8-6:

Either one of transmission method #4-6 or transmission method #6-6.

Transmission Method #8-7:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Transmission Method #8-8:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Transmission Method #8-9:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 64APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Alternatively, two streams are transmitted (s1(i) and s2(i) aretransmitted). The modulation scheme of s1(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 16APSK (a shift may beperformed)), and the modulation scheme of s2(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)). Here, two modulated signals are transmitted. The firstmodulated signal is transmitted using one or more antennas, and thesecond modulated signal is transmitted using one or more antennas. Here,based on FIG. 2 and FIG. 3, precoding (weighted synthesis) is performedusing any one of the (precoding) matrices in Equation (13) throughEquation (20), and thereafter, a phase change is performed (by phasechanger 205B), and the two streams are transmitted (note that a phasechange need not be performed, coefficient multiplication is alsoperformed (by coefficient multipliers 301A, 302A)). Here, θ=0 radians inEquation (13) through Equation (20) (note that θ is greater than orequal to 0 radians and less than a radians (0 radians≤θ<2π radians)).

Alternatively, two streams are transmitted (s1(i) and s2(i) aretransmitted). The modulation scheme of s1(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)), and the modulation scheme of s2(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)). Here, two modulated signals are transmitted. The firstmodulated signal is transmitted using one or more antennas, and thesecond modulated signal is transmitted using one or more antennas. Here,based on FIG. 2 and FIG. 3, precoding (weighted synthesis) is performedusing any one of the (precoding) matrices in Equation (13) throughEquation (20), and thereafter, a phase change is performed (by phasechanger 205B), and the two streams are transmitted (note that a phasechange need not be performed, coefficient multiplication is alsoperformed (by coefficient multipliers 301A, 302A)).

Next, precoding processing will be described.

In the transmission device illustrated in FIG. 1, a plurality ofprecoding matrices expressed by any of Equation (13) through Equation(20) are provided for performing precoding processing. For example, N (Nis an integer that is greater than or equal to 2) precoding matrices areprepared. Here, the N precoding matrices are referred to as i-th matrix(i is an integer that is greater than or equal to 1 and less than orequal to N) (the i-th matrix may be expressed as any one of the matrixesin Equation (13) through Equation (20)).

Based on control signal 200, weighting synthesizer 203 illustrated inFIG. 2, FIG. 3 uses one matrix specified by control signal 200 fromamong the N matrices from the first matrix to the N-th matrix, andperforms precoding.

Note that the N matrices include at least one precoding matrix thatsatisfies any one of Equation (13) through Equation (20) in which θ=0,and include at least one precoding matrix that satisfies any one ofEquation (13) through Equation (20) in which θ≠0.

Note that in the eighth selection method, the transmission method neednot correspond to all transmission methods from transmission method #8-1through transmission method #8-9. For example, in the eighth selectionmethod, the transmission method may correspond to one or moretransmission method from among the following three transmission methods:transmission method #8-5, transmission method #8-6, and transmissionmethod #8-7. In the eighth transmission method, the transmission methodmay correspond to one or more transmission method from among thefollowing two transmission methods: transmission method #8-8 andtransmission method #8-9.

In the eighth selection method, the transmission method need notcorrespond to transmission method #8-1 (in the eighth selection method,the transmission method need not include transmission method #8-1 in thetransmission method selection candidates in the transmission deviceillustrated in FIG. 1). The eighth selection method may include atransmission method other than those from transmission method #8-1 totransmission method #8-9.

Here, the following is satisfied.

Transmission Method #8-1:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 2.

Transmission Method #8-2:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 4.

Transmission Method #8-3:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 16.

Transmission Method #8-4:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 64.

Transmission Method #8-5:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 2 and less than or equalto 4. There are cases in which the advantageous effect of transmitdiversity is achievable.

Transmission Method #8-6:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 4 and less than or equalto 16. There are cases in which the advantageous effect of transmitdiversity is achievable.

Transmission Method #8-7:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 4 and less than or equal to 64. Theadvantageous effect of transmit diversity is achievable.

Transmission Method #8-8:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 16 and less than or equal to 256.The advantageous effect of transmit diversity is achievable.

Transmission Method #8-9:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 64 and less than orequal to 4096. The advantageous effect of transmit diversity may beachievable.

As described above, the selection method for the transmission methodwhen a single-carrier scheme modulated signal is transmitted and theselection method for the transmission method when a multi-carrier schememodulated signal such as an OFDM modulated signal is transmitted aredifferent.

The reason for why the eighth selection method is used as the selectionmethod for the transmission method when a multi-carrier scheme modulatedsignal such as an OFDM modulated signal is transmitted will bedescribed.

As a transmission device that transmits a multi-carrier scheme modulatedsignal such as an OFDM modulated signal, regardless of the modulationscheme used, it is necessary to satisfy the conditions that theinfluence of phase noise in the RF unit is small and the influence ofnon-linear distortion in the transmission power amplifier is small (whenthese conditions are not satisfied, in the reception device thatreceives the modulated signal transmitted by the transmission device, itis difficult to achieve high data reception quality (since thetransmission device transmits modulated signals for a plurality ofcarriers at the same time, regardless of the modulation scheme used, thePAPR is large, so the above-described conditions are important)).

Accordingly, when the transmission device illustrated in FIG. 1 is thethird transmission device (or the first transmission device), by usingthe eighth selection method, when a plurality of modulated signals aretransmitted, it is possible to increase the probability that high datareception quality can be achieved by the reception device, so performingprecoding is given as much priority as possible.

As described above, regardless of whether the transmission devicetransmits a single-carrier scheme modulated signal or a multi-carrierscheme modulated signal such as an OFDM modulated signal, the receptiondevice that receives the modulated signal transmitted by thetransmission device can achieve an advantageous effect that it ispossible to achieve an even higher data reception quality.

Next, a ninth selection method different than the fourth selectionmethod, the fifth selection method, the sixth selection method, theseventh selection method, and the eighth selection method that is usedwhen transmitting a multi-carrier scheme modulated signal such as anOFDM modulated signal will be described.

Ninth Selection Method: Transmission Method #9-1:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is BPSK (or π/2 shift BPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #9-2:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme (of s1(i)) is QPSK (or π/2 shift QPSK) (however, the singlestream modulated signal may be transmitted using a single antenna and,alternatively, transmitted using a plurality of antennas).

Transmission Method #9-3:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or a modulation scheme inwhich 16 signal points are in the in-phase I-quadrature Q plane, such as16APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #9-4:

A single stream is transmitted (s1(i) is transmitted). The modulationscheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or a modulation scheme inwhich 64 signal points are in the in-phase I-quadrature Q plane, such as64APSK (a shift may be performed)) (however, the single stream modulatedsignal may be transmitted using a single antenna and, alternatively,transmitted using a plurality of antennas).

Transmission Method #9-5:

Either one of transmission method #4-5 or transmission method #6-5.

Transmission Method #9-6:

Either one of transmission method #4-6 or transmission method #6-6.

Transmission Method #9-7:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is QPSK (or π/2 shift QPSK), and themodulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Transmission Method #9-8:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 16QAM (or π/2 shift 16QAM) (or amodulation scheme in which 16 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)).

Next, precoding processing will be described.

In the transmission device illustrated in FIG. 1, a plurality ofprecoding matrices expressed by any of Equation (13) through Equation(20) are provided for performing precoding processing. For example, N (Nis an integer that is greater than or equal to 2) precoding matrices areprepared. Here, the N precoding matrices are referred to as i-th matrix(i is an integer that is greater than or equal to 1 and less than orequal to N) (the i-th matrix may be expressed as any one of the matrixesin Equation (13) through Equation (20)).

Based on control signal 200, weighting synthesizer 203 illustrated inFIG. 2, FIG. 3 uses one matrix specified by control signal 200 fromamong the N matrices from the first matrix to the N-th matrix, andperforms precoding.

Note that the N matrices include at least one precoding matrix thatsatisfies any one of Equation (13) through Equation (20) in which θ=0,and include at least one precoding matrix that satisfies any one ofEquation (13) through Equation (20) in which θ≠0.

Transmission Method #9-9:

Two streams are transmitted (s1(i) and s2(i) are transmitted). Themodulation scheme of s1(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 16APSK (a shift may be performed)), andthe modulation scheme of s2(i) is 64QAM (or π/2 shift 64QAM) (or amodulation scheme in which 64 signal points are in the in-phaseI-quadrature Q plane, such as 64APSK (a shift may be performed)). Here,two modulated signals are transmitted. The first modulated signal istransmitted using one or more antennas, and the second modulated signalis transmitted using one or more antennas. Here, based on FIG. 2 andFIG. 3, precoding (weighted synthesis) is performed using any one of the(precoding) matrices in Equation (13) through Equation (20), andthereafter, a phase change is performed (by phase changer 205B), and thetwo streams are transmitted (note that a phase change need not beperformed, coefficient multiplication is also performed (by coefficientmultipliers 301A, 302A)). Here, θ≠0 radians in Equation (13) throughEquation (20) (note that θ is greater than or equal to 0 radians andless than 2π radians (0 radians≤θ<2π radians)).

Alternatively, two streams are transmitted (s1(i) and s2(i) aretransmitted). The modulation scheme of s1(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 16APSK (a shift may beperformed)), and the modulation scheme of s2(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)). Here, two modulated signals are transmitted. The firstmodulated signal is transmitted using one or more antennas, and thesecond modulated signal is transmitted using one or more antennas. Here,based on FIG. 2 and FIG. 3, precoding (weighted synthesis) is performedusing any one of the (precoding) matrices in Equation (13) throughEquation (20), and thereafter, a phase change is performed (by phasechanger 205B), and the two streams are transmitted (note that a phasechange need not be performed, coefficient multiplication is alsoperformed (by coefficient multipliers 301A, 302A)). Here, θ=0 radians inEquation (13) through Equation (20) (note that θ is greater than orequal to 0 radians and less than a radians (0 radians≤θ<2π radians)).

Alternatively, two streams are transmitted (s1(i) and s2(i) aretransmitted). The modulation scheme of s1(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)), and the modulation scheme of s2(i) is 64QAM (or π/2 shift64QAM) (or a modulation scheme in which 64 signal points are in thein-phase I-quadrature Q plane, such as 64APSK (a shift may beperformed)). Here, two modulated signals are transmitted. The firstmodulated signal is transmitted using one or more antennas, and thesecond modulated signal is transmitted using one or more antennas. Here,based on FIG. 2 and FIG. 3, precoding (weighted synthesis) is performedusing any one of the (precoding) matrices in Equation (13) throughEquation (20), and thereafter, a phase change is performed (by phasechanger 205B), and the two streams are transmitted (note that a phasechange need not be performed, coefficient multiplication is alsoperformed (by coefficient multipliers 301A, 302A)).

Next, precoding processing will be described.

In the transmission device illustrated in FIG. 1, a plurality ofprecoding matrices expressed by any of Equation (13) through Equation(20) are provided for performing precoding processing. For example, N (Nis an integer that is greater than or equal to 2) precoding matrices areprepared. Here, the N precoding matrices are referred to as i-th matrix(i is an integer that is greater than or equal to 1 and less than orequal to N) (the i-th matrix may be expressed as any one of the matrixesin Equation (13) through Equation (20)).

Based on control signal 200, weighting synthesizer 203 illustrated inFIG. 2, FIG. 3 uses one matrix specified by control signal 200 fromamong the N matrices from the first matrix to the N-th matrix, andperforms precoding.

Note that the N matrices include at least one precoding matrix thatsatisfies any one of Equation (13) through Equation (20) in which θ=0,and include at least one precoding matrix that satisfies any one ofEquation (13) through Equation (20) in which θ≠0.

Note that in the ninth selection method, the transmission method neednot correspond to all transmission methods from transmission method #9-1to transmission method #9-9. For example, in the ninth selection method,the transmission method may correspond to one or more transmissionmethod from among the following three transmission methods: transmissionmethod #9-5, transmission method #9-6, and transmission method #9-7. Inthe ninth transmission method, the transmission method may correspond toone or more transmission method from among the following twotransmission methods: transmission method #9-8 and transmission method#9-9.

In the ninth selection method, the transmission method need notcorrespond to transmission method #9-1 (in the ninth selection method,the transmission method need not include transmission method #9-1 in thetransmission method selection candidates in the transmission deviceillustrated in FIG. 1).

The ninth selection method may include a transmission method other thanthose from transmission method #9-1 to transmission method #9-9.

Here, the following is satisfied.

Transmission Method #9-1:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 2.

Transmission Method #9-2:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 4.

Transmission Method #9-3:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 16.

Transmission Method #9-4:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is 64.

Transmission Method #9-5:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 2 and less than or equalto 4. There are cases in which the advantageous effect of transmitdiversity is achievable.

Transmission Method #9-6:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 4 and less than or equalto 16. There are cases in which the advantageous effect of transmitdiversity is achievable.

Transmission Method #9-7:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than 4 and less than or equal to 64. Theadvantageous effect of transmit diversity is achievable.

Transmission Method #9-8:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 16 and less than orequal to 256. The advantageous effect of transmit diversity may beachievable.

Transmission Method #9-9:

The number of signal points in the in-phase I-quadrature Q plane of thetransmission signal is greater than or equal to 64 and less than orequal to 4096. The advantageous effect of transmit diversity may beachievable.

As described above, the selection method for the transmission methodwhen a single-carrier scheme modulated signal is transmitted and theselection method for the transmission method when a multi-carrier schememodulated signal such as an OFDM modulated signal is transmitted aredifferent.

The reason for why the ninth selection method is used as the selectionmethod for the transmission method when a multi-carrier scheme modulatedsignal such as an OFDM modulated signal is transmitted will bedescribed.

As a transmission device that transmits a multi-carrier scheme modulatedsignal such as an OFDM modulated signal, regardless of the modulationscheme used, it is necessary to satisfy the conditions that theinfluence of phase noise in the RF unit is small and the influence ofnon-linear distortion in the transmission power amplifier is small (whenthese conditions are not satisfied, in the reception device thatreceives the modulated signal transmitted by the transmission device, itis difficult to achieve high data reception quality (since thetransmission device transmits modulated signals for a plurality ofcarriers at the same time, regardless of the modulation scheme used, thePAPR is large, so the above-described conditions are important)).

Accordingly, when the transmission device illustrated in FIG. 1 is thethird transmission device (or the first transmission device), by usingthe ninth selection method, when a plurality of modulated signals aretransmitted, it is possible to increase the probability that high datareception quality can be achieved by the reception device, so performingprecoding is given as much priority as possible.

As described above, regardless of whether the transmission devicetransmits a single-carrier scheme modulated signal or a multi-carrierscheme modulated signal such as an OFDM modulated signal, the receptiondevice that receives the modulated signal transmitted by thetransmission device can achieve an advantageous effect that it ispossible to achieve an even higher data reception quality.

Next, application examples will be given of a single-carriertransmission method and a multi-carrier scheme transmission method suchas an OFDM transmission method as described above.

For example, assume that communications standard a exists as a radiocommunications method. The frequency band used in communicationsstandard a is predetermined, and in communications standard a, one ormore frequency bands are set. In such cases, communications standard ais capable of both single-carrier modulated signal transmission andmulti-carrier modulated signal transmission, such as OFDM modulatedsignal transmission.

Moreover, communications standard a supports any one of the firstselection method, second selection method, or third selection methoddescribed in Embodiment 1 as single-carrier transmission, and supportsany one of the fourth selection method, fifth selection method, sixthselection method, seventh selection method, eighth selection method, orninth selection method described in this embodiment as multi-carriertransmission such as OFDM transmission.

Accordingly, based on the descriptions of the first transmission device,second transmission device, and third transmission device, the followingthree types of transmission devices can be considered.

Fourth Transmission Device:

The fourth transmission device is a transmission device capable ofselectively transmitting both a single-carrier scheme modulated signalin accordance with communications standard a and a multi-carrier schememodulated signal such as an OFDM modulated signal in accordance withcommunications standard a. Control signal 100 in the transmission deviceillustrated in FIG. 1 includes control information for specifyingtransmission using a single-carrier scheme or transmission using amulti-carrier scheme such as OFDM, and when control signal 100 indicatestransmission using a single-carrier scheme, the transmission deviceillustrated in FIG. 1 transmits a single-carrier scheme modulated signalin accordance with communications standard a, and when control signal100 indicates transmission using a multi-carrier scheme such as OFDM,the transmission device illustrated in FIG. 1 transmits a multi-carrierscheme modulated signal such as an OFDM modulated signal in accordancewith communications standard a. Note that as a result of thetransmission device illustrated in FIG. 1 transmitting, to the receptiondevice illustrated in FIG. 19, control information for specifyingtransmission using a single-carrier scheme or transmission using amulti-carrier scheme such as OFDM, the reception device illustrated inFIG. 19 can receive, demodulate, and decode the modulated signaltransmitted by the transmission device illustrated in FIG. 1.

Fifth Transmission Device:

The fifth transmission device is a transmission device capable oftransmitting a single-carrier scheme modulated signal in accordance withcommunications standard a. When control signal 100 in the transmissiondevice illustrated in FIG. 1 includes control information for specifyingtransmission using a single-carrier scheme or transmission using amulti-carrier scheme such as OFDM, the second transmission device canonly select transmission using a single-carrier scheme as this controlinformation. Accordingly, the transmission device illustrated in FIG. 1transmits a single-carrier scheme modulated signal in accordance withcommunications standard a. Note that as a result of the transmissiondevice illustrated in FIG. 1 transmitting, to the reception deviceillustrated in FIG. 19, control information for specifying transmissionusing a single-carrier scheme or transmission using a multi-carrierscheme such as OFDM, the reception device illustrated in FIG. 19 canreceive, demodulate, and decode the modulated signal transmitted by thetransmission device illustrated in FIG. 1.

Sixth Transmission Device:

The sixth transmission device is a transmission device capable oftransmitting a multi-carrier scheme modulated signal such as an OFDMmodulated signal in accordance with communications standard a. Whencontrol signal 100 in the transmission device illustrated in FIG. 1includes control information for specifying transmission using asingle-carrier scheme or transmission using a multi-carrier scheme suchas OFDM, the second transmission device can only select transmissionusing a multi-carrier scheme such as OFMD as this control information.Accordingly, the transmission device illustrated in FIG. 1 transmits amulti-carrier scheme modulated signal such as a OFDM modulated signal inaccordance with communications standard a. Note that as a result of thetransmission device illustrated in FIG. 1 transmitting, to the receptiondevice illustrated in FIG. 19, control information for specifyingtransmission using a single-carrier scheme or transmission using amulti-carrier scheme such as OFDM, the reception device illustrated inFIG. 19 can receive, demodulate, and decode the modulated signaltransmitted by the transmission device illustrated in FIG. 1.

When the fourth transmission device supports communications standard a,for example, transmission of a single-carrier scheme modulated signal inaccordance with single-carrier scheme and transmission of amulti-carrier scheme modulated signal such as a OFDM signal inaccordance with communications standard a correspond with a common RFunit and common transmission power amplifier in the transmission device,a RF unit and transmission power amplifier that exhibit small influenceof phase noise and non-linear distortion may be used for themulti-carrier scheme modulated signal such as a OFDM signal thatconforms to communications standard a. Accordingly, for thesingle-carrier scheme modulated signal that conforms to communicationsstandard a as well, influence of phase noise and non-linear distortionis small, and with this transmission device, regardless of whether asingle-carrier scheme demodulated signal that conforms to communicationsstandard a or a multi-carrier scheme modulated signal such as a OFDMmodulated signal that conforms to communications standard a istransmitted, the reception device has an advantageous effect that it canachieve a high data reception quality.

Another example is as follows. In the fourth transmission device, when asingle-carrier scheme modulated signal is transmitted in accordance withcommunications standard a, an RF unit and transmission power amplifierthat are dedicated for single-carrier scheme modulated signal usage areused, and when a multi-carrier scheme modulated signal such as an OFDMmodulated signal is transmitted in accordance with communicationsstandard a, an RF unit and transmission power amplifier that arededicated for multi-carrier scheme modulated signal such as OFDMmodulated signal usage are used.

Accordingly, regardless of whether a single-carrier scheme demodulatedsignal that conforms to communications standard a or a multi-carrierscheme modulated signal such as a OFDM modulated signal that conforms tocommunications standard a is transmitted by this transmission device,the reception device has an advantageous effect that it can achieve ahigh data reception quality. Moreover, when this transmission devicetransmits a single-carrier scheme modulated signal in accordance withcommunications standard a, a suitable RF unit and transmission poweramplifier can be used, which yields an advantageous effect that it ispossible to reduce power consumption.

The fifth transmission device transmits a single-carrier schememodulated signal in accordance with communications standard a. Here, asdescribed in Embodiments 1 and 2, the transmission methods that arecapable of performing transmission are limited in the selection methods,and thus, it is possible to reduce PAPR. Accordingly, it is possible toreduce the influence of phase noise and non-linear distortion, and inthe reception device that receives the modulated signal transmitted bythe transmission device, it is possible to achieve an advantageouseffect that data reception quality can be improved, and in thetransmission device, it is possible to achieve an advantageous effectthat an RF unit and transmission power amplifier that are small incircuitry scale and are low-consumption can be used.

The sixth transmission device transmits a multi-carrier scheme modulatedsignal such as an OFDM modulated signal in accordance withcommunications standard a. Here, as described in Embodiment 2, thetransmission methods that are capable of performing transmission arelimited in the selection methods, and thus, in the reception device thatreceives the modulated signal transmitted by the transmission device,there is an advantageous effect that data reception quality is improved.

As described above, in communications standard a that supports bothsingle-carrier transmission and multi-carrier transmission such as OFDMtransmission, it is important that the transmission method forsingle-carrier transmission and the transmission method formulti-carrier transmission such as OFDM transmission include differentaspects. This makes it possible to achieve the advantageous effectsdescribed above.

Note that a spread spectrum communication method may be used for thesingle-carrier scheme modulated signal, and a spread spectrumcommunication method may be used for the multi-carrier scheme modulatedsignal such as a OFDM modulated signal.

(Supplemental Information)

As a matter of course, the present disclosure may be carried out bycombining a plurality of the exemplary embodiments and other contentsdescribed herein.

Moreover, the embodiments are merely examples. For example, while a“modulation scheme, an error correction coding method (error correctioncode, code length, encode rate, etc., to be used), control information,etc.” are exemplified, it is possible to carry out the presentdisclosure with the same configuration even when other types of a“modulation scheme, an error correction coding method (error correctioncode, code length, encode rate, etc., to be used), control information,etc.” are applied.

Regarding the modulation scheme, even when a modulation scheme otherthan the modulation schemes described herein is used, it is possible tocarry out the embodiments and the other subject matter described herein.For example, amplitude phase shift keying (APSK) (such as 16APSK,64APSK, 128APSK, 256APSK, 1024APSK and 4096APSK), pulse amplitudemodulation (PAM) (such as 4PAM, 8PAM, 16PAM, 64PAM, 128PAM, 256PAM,1024PAM and 4096PAM), phase shift keying (PSK) (such as BPSK, QPSK,8PSK, 16PSK, 64PSK, 128PSK, 256PSK, 1024PSK and 4096PSK), and quadratureamplitude modulation (QAM) (such as 4QAM, 8QAM, 16QAM, 64QAM, 128QAM,256QAM, 1024QAM and 4096QAM) may be applied, or in each modulationscheme, uniform mapping or non-uniform mapping may be performed.Moreover, a method for arranging 2, 4, 8, 16, 64, 128, 256, 1024, etc.,signal points on an I-Q plane (a modulation scheme having 2, 4, 8, 16,64, 128, 256, 1024, etc., signal points) is not limited to a signalpoint arrangement method of the modulation schemes described herein.

In the present disclosure, it can be considered that the apparatus whichincludes the transmission device is a communications and broadcastapparatus, such as a broadcast station, a base station, an access point,a terminal or a mobile phone. In such cases, it can be considered thatthe apparatus that includes the reception device is a communicationapparatus such as a television, a radio, a terminal, a personalcomputer, a mobile phone, an access point, or a base station. Moreover,it can also be considered that the transmission device and receptiondevice according to the present disclosure are each a device havingcommunication functions that is formed so as to be connectable via someinterface to an apparatus for executing an application in, for example,a television, a radio, a personal computer or a mobile phone. Moreover,in this embodiment, symbols other than data symbols, such as pilotsymbols (preamble, unique word, post-amble, reference symbol, etc.) orsymbols for control information, may be arranged in any way in a frame.Here, the terms “pilot symbol” and “control information” are used, butthe naming of such symbols is not important; the functions that theyperform are.

A pilot symbol may be a known symbol that is modulated using PSKmodulation in a transceiver (alternatively, a symbol transmitted by atransmitter can be known by a receiver by the receiver being periodic),and the receiver detects, for example, frequency synchronization, timesynchronization, and a channel estimation (channel state information(CSI)) symbol (of each modulated signal) by using the symbol.

Moreover, the symbol for control information is a symbol fortransmitting information required to be transmitted to a communicationpartner in order to establish communication pertaining to anything otherthan data (such as application data) (this information is, for example,the modulation scheme, error correction encoding method, or encode rateof the error correction encoding method used in the communication, orsettings information in an upper layer).

Note that the present invention is not limited to each exemplaryembodiment, and can be carried out with various modifications. Forexample, in each embodiment, the present disclosure is described asbeing performed as a communications device. However, the presentdisclosure is not limited to this case, and this communications methodcan also be used as software.

Note that a program for executing the above-described communicationsmethod may be stored in Read Only Memory (ROM) in advance to cause aCentral Processing Unit (CPU) to operate this program.

Moreover, the program for executing the communications method may bestored in a computer-readable storage medium, the program stored in therecording medium may be recorded in RAM (Random Access Memory) in acomputer, and the computer may be caused to operate according to thisprogram.

Each configuration of each of the above-described embodiments, etc., maybe realized as a LSI (large scale integration) circuit, which istypically an integrated circuit. These integrated circuits may be formedas separate chips, or may be formed as one chip so as to include theentire configuration or part of the configuration of each embodiment.LSI is described here, but the integrated circuit may also be referredto as an IC (integrated circuit), a system LSI circuit, a super LSIcircuit or an ultra LSI circuit depending on the degree of integration.Moreover, the circuit integration technique is not limited to LSI, andmay be realized by a dedicated circuit or a general purpose processor.After manufacturing of the LSI circuit, a programmable FieldProgrammable Gate Array (FPGA) or a reconfigurable processor which isreconfigurable in connection or settings of circuit cells inside the LSIcircuit may be used. Further, when development of a semiconductortechnology or another derived technology provides a circuit integrationtechnology which replaces LSI, as a matter of course, functional blocksmay be integrated by using this technology. Adaption of biotechnology,for example, is a possibility.

Moreover, in the embodiments of the present specification, thedescription of the configuration of the transmission device was givenbased on the configuration illustrated in FIG. 1, but the configurationof the transmission device is not limited to this example; for example,the transmission device may have the configuration illustrated in FIG.22, and further, this may be applied to each of the embodiments.

In FIG. 22, components that operate the same as in FIG. 1 share likereference marks. Accordingly, descriptions that overlap with, forexample, FIG. 1 will be omitted.

FIG. 22 differs in operation from FIG. 1 in that error correctionencoder 102 outputs encoded data 103_1, 103_2. For example, errorcorrection encoder 102 is a component that encodes block code such aslow density parity check (LDPC) code. Here, the 2n−1-th block encodeddata is output as encoded data 103_1, and the 2n-th block encoded datais output as encoded data 103_1 (n is an integer that is greater than orequal to 1).

Mapper 104 performs the modulation scheme mapping specified based onencoded data 103_1 to output mapped signal 105_1, and performs themodulation scheme mapping specified based on encoded data 103_2 tooutput mapped signal 105_2.

Moreover, the embodiments in the present specification described theconfiguration of signal processor 106 illustrated in FIG. 1 and FIG. 22based on the configuration illustrated in FIG. 2, but signal processor106 may have the configuration illustrated in FIG. 23 instead of FIG. 2,and further, this may be applied to each of the embodiments.

In FIG. 23, components that operate the same as in FIG. 2 share likereference marks. Accordingly, descriptions that overlap with, forexample, FIG. 2 will be omitted.

FIG. 23 differs from FIG. 2 in that phase changer 209B illustrated inFIG. 2 is omitted. Accordingly, baseband signal 208A corresponds tosignal-processed signal 106_A in FIG. 1, FIG. 22, and baseband signal208B corresponds to signal-processed signal 106_B in FIG. 1, FIG. 22.

In the present specification, even if the specifics of the transmissiondevice configuration are different, by generating a signal equivalent toany one of signal-processed signal 106_A, 106_B described above in anyof the embodiments of the present specification and transmitting thesignal using a plurality of antenna units, when the reception device isin an environment in which direct waves are dominant, in particular whenin an LOS environment, it is possible to achieve an advantageous effectin which the reception quality of the reception device that isperforming MIMO data symbol transferring (transfer via a plurality ofstreams) can be improved (other advantageous effects described in thepresent specification are also achievable).

Note that in signal processor 106 illustrated in FIG. 1 and FIG. 22, aphase change may be provided both before and after weighting synthesizer203. More specifically, signal processor 106 includes, before weightingsynthesizer 203, one or both of phase changer 205A_1 that generatesphase-changed signal 2801A by applying a phase change to mapped signal201A, and phase changer 205B_1 that generates phase-changed signal 2801Bby applying a phase change to mapped signal 201B. Signal processor 106further includes, before inserter 207A, 207B, one or both of phasechanger 205A_2 that generates phase-changed signal 206A by applying aphase change to weighting synthesized signal 204A, and phase changer205B_2 that generates phase-changed signal 206B by applying a phasechange to weighting synthesized signal 204B.

Here, when signal processor 106 includes phase changer 205A_1, one inputof weighting synthesizer 203 is phase-changed signal 2801A, and whensignal processor 106 does not include phase changer 205A_1, one input ofweighting synthesizer 203 is mapped signal 201A. When signal processor106 includes phase changer 205B_1, the other input of weightingsynthesizer 203 is phase-changed signal 2801B, and when signal processor106 does not include phase changer 205B_1, the other input of weightingsynthesizer 203 is mapped signal 201B. When signal processor 106includes phase changer 205A_2, the input of inserter 207A isphase-changed signal 206A, and when signal processor 106 does notinclude phase changer 205A_2, the input of inserter 207A is weightingsynthesized signal 204A. When signal processor 106 includes phasechanger 205B_2, the input of inserter 207B is phase-changed signal 206B,and when signal processor 106 does not include phase changer 205B_2, theinput of inserter 207B is weighting synthesized signal 204B.

Moreover, the transmission device illustrated in FIG. 1 and FIG. 22 mayinclude a second signal processor that implements different signalprocessing on signal-processed signal 106_A, 106_B, i.e., the output ofsignal processor 106. Here, radio unit 107_A receives an input of signalA processed with second signal processing and performs predeterminedprocessing on the input signal, and radio unit 107_B receives an inputof signal B processed with second signal processing and performspredetermined processing on the input signal, where signal A and signalB processed with second signal processing are two signals output from asecond signal processor.

When signal processor 106 further includes, before inserter 207A, 207B,both of phase changer 205A_2 that generates phase-changed signal 206A byapplying a phase change to weighting synthesized signal 204A, and phasechanger 205B_2 that generates phase-changed signal 206B by applying aphase change to weighting synthesized signal 204B, phase-changed signals206A (z1(i)), 206B(z2(i)) input into inserters 207A, 207B can beexpressed by overwriting the following found in Equation (3) andEquation (37) through Equation (45):

$\begin{matrix}{\left\lbrack {{MATH}.\mspace{14mu} 47} \right\rbrack\mspace{490mu}} & \; \\{\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}{with}} & {{Equation}\mspace{14mu}(47)} \\{\left\lbrack {{MATH}.\mspace{14mu} 48} \right\rbrack\mspace{490mu}} & \; \\\begin{pmatrix}{y_{A}(i)} & 0 \\0 & {y_{B}(i)}\end{pmatrix} & {{Equation}\mspace{14mu}(48)}\end{matrix}$

as a first replacement. When this first replacement is made in Equation(3) and Equation (37) through Equation (45), with respect to allconfigurations described with reference to Equation (3) and Equation(37) through Equation (45) in the present specification, the resultingequations may be applied as variations.

Note that phase change value A(yA(i)) and phase change value B(yB(i)) inthe above equations can respectively be expressed as yA(i)=e^(j×δA(i))and yB(i)=e^(i×δB(i)). Here, δA(i) and δB(i) are real numbers. δA(i) andδB(i) are set such that a result of a modulo operation of the divisor 2πwith respect to δA(i)-δB(i) changes in a cycle N (N is an integer thatis greater than or equal to N) However, how δA(i) and δB(i) are set isnot limited to this example. For example, a method in which phase changevalue A(yA(i)) and phase change value B(yB(i)) each change cyclically orregularly, and the difference (yA(i)/yB(i)) between phase change valuesA and B changes cyclically or regularly may be used.

When signal processor 106 does not include, before inserter 207A, 207B,either one of phase changer 205A_2 that generates phase-changed signal206A by applying a phase change to weighting synthesized signal 204A,and phase changer 205B_2 that generates phase-changed signal 206B byapplying a phase change to weighting synthesized signal 204B,phase-changed signal 206A (z1(i)) and weighting synthesized signal 204B(z2(i)) input into inserters 207A, 207B can be expressed by overwritingthe following found in Equation (3) and Equation (37) through Equation(45):

$\begin{matrix}{\left\lbrack {{MATH}.\mspace{14mu} 49} \right\rbrack\mspace{490mu}} & \; \\{\begin{pmatrix}1 & 0 \\0 & {y(i)}\end{pmatrix}{with}} & {{Equation}\mspace{14mu}(49)} \\{\left\lbrack {{MATH}.\mspace{14mu} 50} \right\rbrack\mspace{490mu}} & \; \\\begin{pmatrix}{y(i)} & 0 \\0 & 1\end{pmatrix} & {{Equation}\mspace{14mu}(50)}\end{matrix}$

as a second replacement. When this second replacement is made inEquation (3) and Equation (37) through Equation (45), with respect toall configurations described with reference to Equation (3) and Equation(37) through Equation (45) in the present specification, the resultingequations may be applied as variations.

For example, phase change value y(i) is set as indicated in Equation(2). However, the method for setting phase change value y(i) is notlimited to the method used in Equation (2); for example, a method inwhich the phase is changed cyclically or regularly is conceivable.

Note that in Embodiment 1, it is described that when the modulationscheme used for mapped signal 201A (s1(i)) is QPSK and the modulationscheme used for mapped signal 201B (s2(i)) is 16QAM, the values for uand v in Equation (37) may be set as follows to achieve good datareception quality in the reception device:

$\begin{matrix}{\left\lbrack {{MATH}.\mspace{14mu} 51} \right\rbrack\mspace{490mu}} & \; \\{u = \sqrt{\frac{2}{3}}} & {{Equation}\mspace{14mu}(51)} \\{\left\lbrack {{MATH}.\mspace{14mu} 52} \right\rbrack\mspace{490mu}} & \; \\{u = \sqrt{\frac{4}{3}}} & {{Equation}\mspace{14mu}(52)} \\{\left\lbrack {{MATH}.\mspace{14mu} 53} \right\rbrack\mspace{490mu}} & \; \\{u = {a \times \sqrt{\frac{2}{3}}}} & {{Equation}\mspace{14mu}(53)} \\{\left\lbrack {{MATH}.\mspace{14mu} 54} \right\rbrack\mspace{490mu}} & \; \\{u = {a \times \sqrt{\frac{4}{3}}}} & {{Equation}\mspace{14mu}(54)}\end{matrix}$

However, examples of settings for the values of u and v that can achievegood data reception quality in the reception device when the modulationscheme used for mapped signal 201A (s1(i)) is QPSK and the modulationscheme used for mapped signal 201B (s2(i)) is 16QAM is not limited tothe combination of Equation (51) and Equation (52) and the combinationof Equation (53) and Equation (54).

Consider the following two examples.

Consider, as the first example, that the error correction encodingscheme used by error correction encoder 102 to generate encoded data 103is selectable between a first error correction encoding scheme and asecond error correction encoding scheme that is different from the firsterror correction encoding scheme in regard to one or both of the encoderate and code length.

Consider, as the second example, that a plurality of the errorcorrection encoders illustrated in FIG. 1 are provided, and in any oneof the error correction encoders, one or both of the encode rate andcode length of the error correction code are changed.

Next, the first and second examples will be discussed further.

Mapper 104 uses a first modulation scheme to generate mapped signal 201A(s1(i)), and uses a second modulation scheme different from the firstmodulation scheme to generate mapped signal 201B (s2(i)). Here, whensignal processor 106 uses the first error correction encoding scheme asthe error correction encoding scheme and uses the first and secondmodulation schemes as a combination of modulation schemes, values u1 andv1 are used as the values for u and v, respectively, in Equation (37).Moreover, when signal processor 106 uses the second error correctionencoding scheme as the error correction encoding scheme and uses thefirst and second modulation schemes as a combination of modulationschemes, values u2 and v2 are used as the values for u and v,respectively, in Equation (37). Here, when the ratio of u1 and v1differs from the ratio of u2 and v2, compared to when the ratio of u1and v1 is the same as the ratio of u2 and v2, there is a probabilitythat the reception device can achieve good data reception quality.

Note that in the above description, the ratio of values of u and v inEquation (37) was described as being changed when the encode rate orcode length or both of the error correction encoding scheme used byerror correction encoder 102 to generate encoded data 103 is different,but the ratio of the u and v values may be changed based on conditionsother than the encode rate or code length of the error correctionencoding scheme. For example, signal processor 106 may change the ratioof the u and v values in accordance with a combination of modulationschemes used as the first modulation scheme and the second modulationscheme. Furthermore, as one other example, even when error correctionencoding schemes are equal and the combination of modulation schemesused as the first modulation scheme and the second modulation scheme areequal, signal processor 106 may change the ratio of the values of u andv so as to differ between when a single-carrier scheme modulated signalis transmitted and a multi-carrier scheme modulated signal such as anOFDM modulated signal is transmitted. This configuration makes itpossible for reception device to achieve good data reception quality.

INDUSTRIAL APPLICABILITY

The present disclosure is applicable in radio communications systemsusing a single-carrier scheme and/or a multi-carrier scheme.

REFERENCE MARKS IN THE DRAWINGS

-   100 control signal-   101 data-   102 error correction encoder-   103 encoded data-   104 mapper-   105_1, 105_2 baseband signal-   106 signal processor-   106_A, 106_B signal-processed signal-   107_A, 107_B radio unit-   108_A, 108_B transmission signal-   109_A, 109_B antenna unit

What is claimed is:
 1. A transmission method, comprising: modulatingquadrature phase shift keying (QPSK) points s1(i) by using bits of afirst stream and 16-quadrature amplitude modulation (QAM) points s2(i)by using bits of a second stream, where i is a symbol number; convertingthe QPSK points s1(i) and the 16-QAM points s2(i) to first convertedpoints z1(i) and second converted points z2(i), wherein the firstconverted points z1(i) and the second converted points z2(i) are definedas: ${\begin{pmatrix}{z1(i)} \\{z2(i)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & e^{j{\delta{(i)}}}\end{pmatrix}\begin{pmatrix}{\cos\frac{\pi}{4}} & {\sin\frac{\pi}{4}} \\{\sin\frac{\pi}{4}} & {{- \cos}\frac{\pi}{4}}\end{pmatrix}\begin{pmatrix}\sqrt{2/3} & 0 \\0 & \sqrt{4/3}\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}},$ where j is an imaginary number unit, and δ(i) is areal number incremented by a constant value for every i; and generatingone or more orthogonal frequency division multiplexing (OFDM) symbolsthat include the first converted points z1(i) and the second convertedpoints z2(i).
 2. The transmission method of claim 1, wherein a value ofδ(i) periodically varies with a period of N, wherein N is an integer. 3.The transmission method of claim 2, wherein N is eight.
 4. Thetransmission method of claim 1, wherein the constant value is 2π/N,where N is an integer greater than or equal to two.
 5. The transmissionmethod of claim 1, wherein e^(jδ(i)) is a phase change value.
 6. Thetransmission method of claim 1, further comprising: transmitting the oneor more OFDM symbols using one or more antennas
 7. A transmissiondevice, comprising: a mapper to modulate quadrature phase shift keying(QPSK) points s1(i) by using bits of a first stream and 16-quadratureamplitude modulation (QAM) points s2(i) by using bits of a secondstream, where i is a symbol number; a signal processor to convert theQPSK points s1(i) and the 16-QAM points s2(i) to first converted pointsz1(i) and second converted points z2(i), wherein the first convertedpoints z1(i) and the second converted points z2(i) are defined as:${\begin{pmatrix}{z1(i)} \\{z2(i)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & e^{j{\delta{(i)}}}\end{pmatrix}\begin{pmatrix}{\cos\frac{\pi}{4}} & {\sin\frac{\pi}{4}} \\{\sin\frac{\pi}{4}} & {{- \cos}\frac{\pi}{4}}\end{pmatrix}\begin{pmatrix}\sqrt{2/3} & 0 \\0 & \sqrt{4/3}\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}},$ where j is an imaginary number unit, and δ(i) is areal number incremented by a constant value for every i; and a generatorto generate one or more orthogonal frequency division multiplexing(OFDM) symbols that include the first converted points z1(i) and thesecond converted points z2(i).
 8. The transmission device of claim 7,wherein a value of δ(i) periodically varies with a period of N, whereinN is an integer.
 9. The transmission device of claim 8, wherein N iseight.
 10. The transmission device of claim 7, wherein the constantvalue is 2π/N, where N is an integer greater than or equal to two. 11.The transmission device of claim 7, wherein e^(jδ(i)) is a phase changevalue.
 12. The transmission device of claim 11, further comprising: atransmitter to transmit the one or more symbols using one or moreantennas.
 13. A reception method, comprising: obtaining a receptionsignal by receiving one or more orthogonal frequency divisionmultiplexing (OFDM) symbols that includes first converted signals z1(i)and second converted signals z2(i) transmitted by using one or moreantennas, where i is a symbol number, wherein the first convertedsignals z1(i) and the second converted signals z2(i) are generated byconverting quadrature phase shift keying (QPSK) points s1(i) and16-quadrature amplitude modulation (QAM) points s2(i), the QPSK pointss1(i) are modulated by using bits of a first stream and the 16-QAMpoints s2(i) are modulated by using bits of a second stream, the firstconverted signals z1(i) and the second converted signals z2(i) aredefined as: ${\begin{pmatrix}{z1(i)} \\{z2(i)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & e^{j{\delta{(i)}}}\end{pmatrix}\begin{pmatrix}{\cos\frac{\pi}{4}} & {\sin\frac{\pi}{4}} \\{\sin\frac{\pi}{4}} & {{- \cos}\frac{\pi}{4}}\end{pmatrix}\begin{pmatrix}\sqrt{2/3} & 0 \\0 & \sqrt{4/3}\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}},$ where j is an imaginary number unit, and δ(i) is areal number incremented by a constant value for every i; anddemodulating the reception signal according to a conversion applied tothe QPSK points s1(i) and the 16-QAM points s2(i).
 14. The receptionmethod of claim 13, wherein a value of δ(i) periodically varies with aperiod of N, wherein N is an integer.
 15. The reception method of claim13, wherein N is eight.
 16. The reception method of claim 13, whereinthe constant value is 2π/N, where N is an integer greater than or equalto two.
 17. The reception method of claim 13, wherein e^(jδ(i)) is aphase change value.
 18. A reception device, comprising: a receiver toobtain a reception signal by receiving one or more orthogonal frequencydivision multiplexing (OFDM) symbols that include first convertedsignals z1(i) and second converted signals z2(i) transmitted by usingone or more antennas, where i is a symbol number, wherein the firstconverted signals z1(i) and the second converted signals z2(i) aregenerated by converting quadrature phase shift keying (QPSK) pointss1(i) and 16-quadrature amplitude modulation (QAM) points s2(i), theQPSK points s1(i) are modulated by using bits of a first stream and the16-QAM points s2(i) are modulated by using bits of a second stream, thefirst converted signals z1(i) and the second converted signals z2(i) aredefined as: ${\begin{pmatrix}{z1(i)} \\{z2(i)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & e^{j{\delta{(i)}}}\end{pmatrix}\begin{pmatrix}{\cos\frac{\pi}{4}} & {\sin\frac{\pi}{4}} \\{\sin\frac{\pi}{4}} & {{- \cos}\frac{\pi}{4}}\end{pmatrix}\begin{pmatrix}\sqrt{2/3} & 0 \\0 & \sqrt{4/3}\end{pmatrix}\begin{pmatrix}{s1(i)} \\{s2(i)}\end{pmatrix}}},$ where j is an imaginary number unit, and δ(i) is areal number incremented by a constant value for every i; and ademodulator to demodulate the reception signal according to a conversionapplied to the QPSK points s1(i) and the 16-QAM points s2(i).
 19. Thereception device of claim 18, wherein a value of δ(i) periodicallyvaries with a period of N, wherein N is an integer.
 20. The receptiondevice of claim 19, wherein N is eight.
 21. The reception device ofclaim 18, wherein the constant value is 2π/N, where N is an integergreater than or equal to two.
 22. The reception device of claim 18,wherein e^(jδ(i)) is a phase change value.